Remove proc_raise and the signal types and constants.

WebAssembly doesn't support signal handling, so these weren't
useful for their main purpose. The one thing you could do with
`proc_raise` was terminate execution with a signal status,
however that's not super useful and even wasi-libc didn't make
use of it in its abort function.

Author: sunfishcode

phases/ephemeral/docs/wasi_ephemeral_preview.md

@@ -106,7 +106,6 @@ modules so that embedders need not implement all of it.
 - [`__wasi_path_unlink_file()`](#path_unlink_file)
 - [`__wasi_poll_oneoff()`](#poll_oneoff)
 - [`__wasi_proc_exit()`](#proc_exit)
-- [`__wasi_proc_raise()`](#proc_raise)
 - [`__wasi_random_get()`](#random_get)
 - [`__wasi_sched_yield()`](#sched_yield)
 - [`__wasi_sock_recv()`](#sock_recv)
@@ -951,18 +950,6 @@ Inputs:
 
 Does not return.
 
-### <a href="#proc_raise" name="proc_raise"></a>`__wasi_proc_raise()`
-
-Send a signal to the process of the calling thread.
-
-Note: This is similar to `raise` in POSIX.
-
-Inputs:
-
-- <a href="#proc_raise.sig" name="proc_raise.sig"></a><code>[\_\_wasi\_signal\_t](#signal) <strong>sig</strong></code>
-
-    The signal condition to trigger.
-
 ### <a href="#random_get" name="random_get"></a>`__wasi_random_get()`
 
 Write high-quality random data into a buffer.
@@ -2057,194 +2044,6 @@ defined, it must be set to zero.
 
 Used by [`__wasi_sock_send()`](#sock_send).
 
-### <a href="#signal" name="signal"></a>`__wasi_signal_t` (`uint8_t`)
-
-Signal condition.
-
-Used by [`__wasi_proc_raise()`](#proc_raise).
-
-Possible values:
-
-- <a href="#signal.hup" name="signal.hup"></a>**`__WASI_SIGHUP`**
-
-    Hangup.
-
-    Action: Terminates the process.
-
-- <a href="#signal.int" name="signal.int"></a>**`__WASI_SIGINT`**
-
-    Terminate interrupt signal.
-
-    Action: Terminates the process.
-
-- <a href="#signal.quit" name="signal.quit"></a>**`__WASI_SIGQUIT`**
-
-    Terminal quit signal.
-
-    Action: Terminates the process.
-
-- <a href="#signal.ill" name="signal.ill"></a>**`__WASI_SIGILL`**
-
-    Illegal instruction.
-
-    Action: Terminates the process.
-
-- <a href="#signal.trap" name="signal.trap"></a>**`__WASI_SIGTRAP`**
-
-    Trace/breakpoint trap.
-
-    Action: Terminates the process.
-
-- <a href="#signal.abrt" name="signal.abrt"></a>**`__WASI_SIGABRT`**
-
-    Process abort signal.
-
-    Action: Terminates the process.
-
-- <a href="#signal.bus" name="signal.bus"></a>**`__WASI_SIGBUS`**
-
-    Access to an undefined portion of a memory object.
-
-    Action: Terminates the process.
-
-- <a href="#signal.fpe" name="signal.fpe"></a>**`__WASI_SIGFPE`**
-
-    Erroneous arithmetic operation.
-
-    Action: Terminates the process.
-
-- <a href="#signal.kill" name="signal.kill"></a>**`__WASI_SIGKILL`**
-
-    Kill.
-
-    Action: Terminates the process.
-
-- <a href="#signal.usr1" name="signal.usr1"></a>**`__WASI_SIGUSR1`**
-
-    User-defined signal 1.
-
-    Action: Terminates the process.
-
-- <a href="#signal.segv" name="signal.segv"></a>**`__WASI_SIGSEGV`**
-
-    Invalid memory reference.
-
-    Action: Terminates the process.
-
-- <a href="#signal.usr2" name="signal.usr2"></a>**`__WASI_SIGUSR2`**
-
-    User-defined signal 2.
-
-    Action: Terminates the process.
-
-- <a href="#signal.pipe" name="signal.pipe"></a>**`__WASI_SIGPIPE`**
-
-    Write on a pipe with no one to read it.
-
-    Action: Ignored.
-
-- <a href="#signal.alrm" name="signal.alrm"></a>**`__WASI_SIGALRM`**
-
-    Alarm clock.
-
-    Action: Terminates the process.
-
-- <a href="#signal.term" name="signal.term"></a>**`__WASI_SIGTERM`**
-
-    Termination signal.
-
-    Action: Terminates the process.
-
-- <a href="#signal.chld" name="signal.chld"></a>**`__WASI_SIGCHLD`**
-
-    Child process terminated, stopped, or continued.
-
-    Action: Ignored.
-
-- <a href="#signal.cont" name="signal.cont"></a>**`__WASI_SIGCONT`**
-
-    Continue executing, if stopped.
-
-    Action: Continues executing, if stopped.
-
-- <a href="#signal.stop" name="signal.stop"></a>**`__WASI_SIGSTOP`**
-
-    Stop executing.
-
-    Action: Stops executing.
-
-- <a href="#signal.tstp" name="signal.tstp"></a>**`__WASI_SIGTSTP`**
-
-    Terminal stop signal.
-
-    Action: Stops executing.
-
-- <a href="#signal.ttin" name="signal.ttin"></a>**`__WASI_SIGTTIN`**
-
-    Background process attempting read.
-
-    Action: Stops executing.
-
-- <a href="#signal.ttou" name="signal.ttou"></a>**`__WASI_SIGTTOU`**
-
-    Background process attempting write.
-
-    Action: Stops executing.
-
-- <a href="#signal.urg" name="signal.urg"></a>**`__WASI_SIGURG`**
-
-    High bandwidth data is available at a socket.
-
-    Action: Ignored.
-
-- <a href="#signal.xcpu" name="signal.xcpu"></a>**`__WASI_SIGXCPU`**
-
-    CPU time limit exceeded.
-
-    Action: Terminates the process.
-
-- <a href="#signal.xfsz" name="signal.xfsz"></a>**`__WASI_SIGXFSZ`**
-
-    File size limit exceeded.
-
-    Action: Terminates the process.
-
-- <a href="#signal.vtalrm" name="signal.vtalrm"></a>**`__WASI_SIGVTALRM`**
-
-    Virtual timer expired.
-
-    Action: Terminates the process.
-
-- <a href="#signal.prof" name="signal.prof"></a>**`__WASI_SIGPROF`**
-
-    Profiling timer expired.
-
-    Action: Terminates the process.
-
-- <a href="#signal.winch" name="signal.winch"></a>**`__WASI_SIGWINCH`**
-
-    Window changed.
-
-    Action: Ignored.
-
-- <a href="#signal.poll" name="signal.poll"></a>**`__WASI_SIGPOLL`**
-
-    I/O possible.
-
-    Action: Terminates the process.
-
-- <a href="#signal.pwr" name="signal.pwr"></a>**`__WASI_SIGPWR`**
-
-    Power failure.
-
-    Action: Terminates the process.
-
-- <a href="#signal.sys" name="signal.sys"></a>**`__WASI_SIGSYS`**
-
-    Bad system call.
-
-    Action: Terminates the process.
-
 ### <a href="#subclockflags" name="subclockflags"></a>`__wasi_subclockflags_t` (`uint16_t` bitfield)
 
 Flags determining how to interpret the timestamp provided in

phases/ephemeral/witx/typenames.witx

@@ -601,105 +601,6 @@
 ;;; Exit code generated by a process when exiting.
 (typename $exitcode u32)
 
-;;; Signal condition.
-(typename $signal
-  (enum u8
-    ;;; No signal. Note that POSIX has special semantics for `kill(pid, 0)`,
-    ;;; so this value is reserved.
-    $none
-    ;;; Hangup.
-    ;;; Action: Terminates the process.
-    $hup
-    ;;; Terminate interrupt signal.
-    ;;; Action: Terminates the process.
-    $int
-    ;;; Terminal quit signal.
-    ;;; Action: Terminates the process.
-    $quit
-    ;;; Illegal instruction.
-    ;;; Action: Terminates the process.
-    $ill
-    ;;; Trace/breakpoint trap.
-    ;;; Action: Terminates the process.
-    $trap
-    ;;; Process abort signal.
-    ;;; Action: Terminates the process.
-    $abrt
-    ;;; Access to an undefined portion of a memory object.
-    ;;; Action: Terminates the process.
-    $bus
-    ;;; Erroneous arithmetic operation.
-    ;;; Action: Terminates the process.
-    $fpe
-    ;;; Kill.
-    ;;; Action: Terminates the process.
-    $kill
-    ;;; User-defined signal 1.
-    ;;; Action: Terminates the process.
-    $usr1
-    ;;; Invalid memory reference.
-    ;;; Action: Terminates the process.
-    $segv
-    ;;; User-defined signal 2.
-    ;;; Action: Terminates the process.
-    $usr2
-    ;;; Write on a pipe with no one to read it.
-    ;;; Action: Ignored.
-    $pipe
-    ;;; Alarm clock.
-    ;;; Action: Terminates the process.
-    $alrm
-    ;;; Termination signal.
-    ;;; Action: Terminates the process.
-    $term
-    ;;; Child process terminated, stopped, or continued.
-    ;;; Action: Ignored.
-    $chld
-    ;;; Continue executing, if stopped.
-    ;;; Action: Continues executing, if stopped.
-    $cont
-    ;;; Stop executing.
-    ;;; Action: Stops executing.
-    $stop
-    ;;; Terminal stop signal.
-    ;;; Action: Stops executing.
-    $tstp
-    ;;; Background process attempting read.
-    ;;; Action: Stops executing.
-    $ttin
-    ;;; Background process attempting write.
-    ;;; Action: Stops executing.
-    $ttou
-    ;;; High bandwidth data is available at a socket.
-    ;;; Action: Ignored.
-    $urg
-    ;;; CPU time limit exceeded.
-    ;;; Action: Terminates the process.
-    $xcpu
-    ;;; File size limit exceeded.
-    ;;; Action: Terminates the process.
-    $xfsz
-    ;;; Virtual timer expired.
-    ;;; Action: Terminates the process.
-    $vtalrm
-    ;;; Profiling timer expired.
-    ;;; Action: Terminates the process.
-    $prof
-    ;;; Window changed.
-    ;;; Action: Ignored.
-    $winch
-    ;;; I/O possible.
-    ;;; Action: Terminates the process.
-    $poll
-    ;;; Power failure.
-    ;;; Action: Terminates the process.
-    $pwr
-    ;;; Bad system call.
-    ;;; Action: Terminates the process.
-    $sys
-  )
-)
-
 ;;; Flags provided to `sock_recv`.
 (typename $riflags
   (flags u16

phases/ephemeral/witx/wasi_ephemeral_preview.witx

@@ -463,14 +463,6 @@
     (param $rval $exitcode)
   )
 
-  ;;; Send a signal to the process of the calling thread.
-  ;;; Note: This is similar to `raise` in POSIX.
-  (@interface func (export "proc_raise")
-    ;;; The signal condition to trigger.
-    (param $sig $signal)
-    (result $error $errno)
-  )
-
   ;;; Temporarily yield execution of the calling thread.
   ;;; Note: This is similar to `sched_yield` in POSIX.
   (@interface func (export "sched_yield")