`__NoopCoro_ResumeDestroy` currently has private linkage, which causes
[issues for
Arm64EC](https://github.com/llvm/llvm-project/issues/158341). The
Arm64EC lowering is trying to mangle and add thunks for
`__NoopCoro_ResumeDestroy`, since it sees that it's address is taken
(and, therefore, might be called from x64 code via a function pointer).
MSVC's linker requires that the function be placed in COMDAT (`LNK1361:
non COMDAT symbol '.L#__NoopCoro_ResumeDestroy' in hybrid binary`) which
trips an assert in the verifier (`comdat global value has private
linkage`) and the subsequent linking step fails since the private symbol
isn't in the symbol table.
Since there is no reason to use private linkage for
`__NoopCoro_ResumeDestroy` and other coro related functions have also
been [switched to internal linkage to improve
debugging](https://github.com/llvm/llvm-project/pull/151224), this
change switches to using internal linkage.
Fixes#158341
4fabe6ffae