LWG-3819 `reference_meows_from_temporary` should not use `is_meowible`

[StephanTLavavej]

LWG-3819 reference_meows_from_temporary should not use is_meowible

In #5537, A. Jiang (@frederick-vs-ja) said:

LWG-3819 has not been implemented. Because Clang's intrinsics haven't covered these cases, and library workaround doesn't seem possible.

Even if the resolution for this LWG issue needs to happen in the compilers, we still need test coverage when that becomes available. Per Jonathan Emmett (@joemmett) in VSO-3000560, "Our implementation does not use is_meowable to determine these traits so we should be LWG-3819 compliant already."

[frederick-vs-ja]

I implemented this for Clang in LLVM-142554 and the changes landed in Clang 21.