Add test for issue rust-lang#34634

Author: bugadani

src/test/codegen/issue-34634.rs

@@ -0,0 +1,16 @@
+// Test that `wrapping_div` only checks divisor once.
+// This test checks that there is only a single compare agains -1 and -1 is not present as a
+// switch case (the second check present until rustc 1.12).
+// This test also verifies that a single panic call is generated (for the division by zero case).
+
+// compile-flags: -O
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @f
+#[no_mangle]
+pub fn f(x: i32, y: i32) -> i32 {
+    // CHECK-COUNT-1: icmp eq i32 %y, -1
+    // CHECK-COUNT-1: panic
+    // CHECK-NOT: i32 -1, label
+    x.wrapping_div(y)
+}