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

[Heejin Ahn via llvm-commits]

aheejin wrote:

> That's not how it works for command line flags corresponding to other unsupported TargetOptions, they are silently unused: https://godbolt.org/z/hszPh535h

Can you point out what are the unsupported options here?

> There are also [other targets doing similar things](https://github.com/llvm/llvm-project/blob/f435f55d58542ecde0e66460555ccbcbca355cc5/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp#L334) that do not warn when they are overriding command line options: https://godbolt.org/z/j9rhrcn9E

I don't object to overriding. I'm suggesting a warning _only when an incompatible option is explicitly given in the command line_.

> This PR matches what already exists. If you want to add warnings and errors to these command line options, then you should open a separate issue.

If you grep with `report_fatal_error` in all target's `***TargetMachine.cpp`, there are many instances of reporting that some options are not supported. (I'm not necessarily suggesting erroring out though)

Also, can you please address my other unrelated comments?

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