This is modelled after how the ELF driver does it; we need to
intercept some options, but ignore GCC specific ones that GCC
passes regardless of whether GCC is using LTO or not.
This is the second part of the fix for
https://github.com/mstorsjo/llvm-mingw/issues/349.
Test that we ignore -plugin-opt=...lto-wrapper.exe as well. If lto-wrapper.exe is not present, remove the special case !v.ends_with("lto-wrapper.exe")