IntelLLVM: Pass linker flags to the compiler when used as linker

When linking an executable, DLL, or static library, the compiler sometimes
needs to see the linking options.  Typically `<FLAGS>` is not passed
for linking, because some of the options are only used for compilation.
Previously, `<LINK_FLAGS>` was passed after the `/link` flag because
the compiler did not understand some of the linking options.

This change wraps the initial linker options borrowed from Windows-MSVC
individually, so that they are passed directly to the linker.

This change is helpful both for interprocedural optimization, which needs
to pass `-Qipo` to the compiler at link time, and for SYCL which needs
to pass `-fsycl` and possibly other options to the compiler at link time.

Signed-off-by: William R. Dieter <william.r.dieter@intel.com>