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

[Matt Harding via llvm-commits]

majaha wrote:

The counterexample is this:
```llvm
declare void @ext_never_return() noreturn

define i32 @missing_ret_noreturn_unreach() {
  call void @ext_never_return()
  unreachable
}
```
Which, when compiled with `TargetOptions.NoTrapAfterNoreturn = true`, outputs:
```wasm
missing_ret_noreturn_unreach:
.functype missing_ret_noreturn_unreach () -> (i32)
 # %bb.0:
   call ext_never_return
   end_function
```
which *should* be
```wasm
missing_ret_noreturn_unreach:
.functype missing_ret_noreturn_unreach () -> (i32)
 # %bb.0:
   call ext_never_return
   unreachable
   end_function
```

> Also what is the case in which it is safe to remove, as I asked in https://github.com/llvm/llvm-project/pull/65876#discussion_r1332296556?

I'm not sure I understand the question. When is what safe to remove, exactly?

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