* gcc.c (target_sysroot_suffix, target_sysroot_hdrs_suffix,
SYSROOT_SUFFIX_SPEC, SYSROOT_HEADERS_SUFFIX_SPEC, sysroot_suffix_spec,
sysroot_hdrs_suffix_spec): New.
(static_specs): Initialize new variables.
(add_sysroot_suffix_prefix, do_spec_1, main): Use new variables.
* doc/tm.texi (SYSROOT_SUFFIX_SPEC, SYSROOT_HEADERS_SUFFIX_SPEC):
New macros.

From-SVN: r68223