gcc.c (option_map): Add --sysroot.
* gcc.c (option_map): Add --sysroot.
(process_command): Handle --sysroot.
(display_help): Document it.
* doc/cppopts.tex (-isysroot): Document.
* doc/invoke.texi (--sysroot): Document.
* doc/install.texi (--with-build-sysroot): Document.
* Makefile.in (inhibit_libc): New variable.
(INHIBIT_LIBC_CFLAGS): Likewise.
(LIBGCC2_CFLAGS): Include
$(INHIBIT_LIBC_CFLAGS).
(CRTSTUFF_CFLAGS): Include $(INHIBIT_LIBC_CFLAGS).
($(T)crtbegin.o): Do not use @inhibit_libc@.
($(T)crtend.o): Likewise.
($(T)crtbeginS.o): Do not use @inhibit_libc@.
($(T)crtendS.o): Likewise.
($(T)crtbeginT.o): Do not use @inhibit_libc@.
($(T)crtendT.o): Likewise.
(stmp-fixinc): Do not complain about missing headers if
inhibit_libc.
* configure.ac (inhibit_libc): Set it to true/false.
(--with-build-sysroot): New option. Use it to set
SYSTEM_HEADER_DIR.
* configure: Regenerated.
From-SVN: r102367