[lld] [llvm] [llvm-lib][llvm-dlltool][Object] Add support for EXPORTAS name types. (PR #78772)

[Jacek Caban via llvm-commits]

cjacek wrote:

MinGW extension adds a COFF object to import library that creates a weak external symbol. EXPORTAS is extends short import file format to store export name separate from symbol name.

https://github.com/llvm/llvm-project/pull/78772