[LLD] [COFF] Include "rust_eh_personality" among the known personality functions

These need to have special treatment wrt to .eh_frame sections
and GC - as long as we don't have a full parser of the .eh_frame
section in the COFF linker.

This fixes Rust unwind issues on i686 mingw as discussed in
https://github.com/msys2/MINGW-packages/issues/9091.

Differential Revision: https://reviews.llvm.org/D136879