nacl-clang driver: Derive nacltools::Link from gnutools::Link

The GnuTool subclass of Tool handles enabling response-file support,
which matters on Windows.  Using gnutools::Link as the base class
rather than just changing Tool to GnuTool seems like the cleaner
solution, as it avoids the need to duplicate the other methods.
Only ConstructJob actually differs from gnutools::Link.

BUG= 512869
TEST= toolchain trybots

Review URL: .
1 file changed