Add regression test for ICE rust-lang#4579

Author: flip1995

tests/ui/ice-4579.rs

@@ -0,0 +1,14 @@
+#![allow(clippy::single_match)]
+
+use std::ptr;
+
+fn main() {
+    match Some(0_usize) {
+        Some(_) => {
+            let s = "012345";
+            unsafe { ptr::read(s.as_ptr().offset(1) as *const [u8; 5]) };
+            //                                                     ^ No expr_ty for this expr
+        },
+        _ => (),
+    };
+}