[clang] [Clang][Driver] Revise Cygwin ToolChain to call linker directly (PR #147960)

[Martin Storsjö via cfe-commits]

mstorsjo wrote:

> Weak symbols do not work out well in PE/COFF

They work just fine in clang+lld environments for mingw targets, but there's a handful of known issues relating to them with gcc+ld.bfd, for mingw. But apparently those issues don't hit cygwin targets.

https://github.com/llvm/llvm-project/pull/147960