Makefile.in: Revamp handling of cflags to allow different WARN_CFLAGS for compilations in...

        * Makefile.in: Revamp handling of cflags to allow different WARN_CFLAGS
        for compilations in stage 1 and subsequent stages, respectively.
        * configure.in (vax): Add compiler-dependent CFLAGS for stage 1.
        * configure: Rebuilt.
        * x-vax, x-vax-gcc: Deleted.

From-SVN: r36059