RFC:
https://discourse.llvm.org/t/rfc-cmake-linker-flags-need-wl-equivalent-for-intel-c-icx-on-windows/82446
The Intel C++ Compiler (ICX) passes linker flags through the driver
unlike MSVC and clang-cl, and therefore needs them to be prefixed with
`/Qoption,link` (the equivalent of `-Wl,` for gcc on *nix).
Previous PRs did not catch this because I did not try building with
`LLVM_BUILD_INSTRUMENTED=ON`.
`CMAKE_CXX_LINKER_WRAPPER_FLAG` is empty for plain clang-cl (icx on
windows behaves as clang-cl), so this is NFC for clang-cl.
e1b5826c2b