[clang] Ensure NoTrapAfterNoreturn is false for the wasm backend (PR #65876)

[Heejin Ahn via cfe-commits]

================
@@ -85,7 +81,8 @@ define i32 @missing_ret_unreachable() {
 }
 
 ; This is similar to the above test, but ensures wasm unreachable is emitted
-; even after a noreturn call.
+; even after a noreturn call. Using --no-trap-after-noreturn was previously
+; known to break this.
----------------
aheejin wrote:

```suggestion
; This is similar to the above test, but the callee has a 'noreturn' attribute.    
; There is an optimization that removes an 'unreachable' after a noreturn call,  
; but Wasm backend doesn't use it and ignore `--no-trap-after-noreturn`, if      
; given, to generate valid code. 
```

https://github.com/llvm/llvm-project/pull/65876