global module fragment
[basic.stc.dynamic.general]p2 says:
> The library provides default definitions for the global allocation
> and deallocation functions. Some global allocation and
> deallocation
> functions are replaceable ([new.delete]); these are attached to
> the global module ([module.unit]).
But we didn't take this before and the implicitly generated functions
will live in the module purview if we're compiling a module unit. This
is bad since the owning module will affect the linkage of the
declarations. This patch addresses this.
Closes https://github.com/llvm/llvm-project/issues/58560
Chuanqi Xu