libgomp.exp (libgomp_target_compile): If $source matches regex $lang_source_re, add $lang_include_flags to options.

	* testsuite/lib/libgomp.exp (libgomp_target_compile): If $source
	matches regex $lang_source_re, add $lang_include_flags to options.
	* testsuite/libgomp.c/c.exp: Unset lang_include_flags.
	* testsuite/libgomp.c++/c++.exp: Likewise.
	* testsuite/libgomp.fortran/fortran.exp: Likewise.  Set lang_source_re
	and lang_include_flags instead of adding -fintrinsic-modules-path= to
	ALWAYS_CFLAGS.
	* testsuite/libgomp.graphite/graphite.exp: Unset lang_include_flags.

From-SVN: r212268