Replace the old --with-cxx-* configure options with a single --with-gcc-toolchain
that just uses the new toolchain probing logic. This fixes linking with -m32 on
64 bit systems (the /32 dir was not being added to the search).

llvm-svn: 149651
GitOrigin-RevId: ec217f6ad66e681b29186f95b8f971d59adf3cbb
7 files changed