Enable building libsanitizer with Intel CET

libsanitizer/
	* acinclude.m4: Add enable.m4 and cet.m4.
	* Makefile.in: Regenerate.
	* asan/Makefile.am: Update AM_CXXFLAGS.
	* asan/Makefile.in: Regenerate.
	* configure: Likewise.
	* configure.ac: Set CET_FLAGS. Update EXTRA_CFLAGS,
	EXTRA_CXXFLAGS, EXTRA_ASFLAGS.
	* interception/Makefile.am: Update AM_CXXFLAGS.
	* interception/Makefile.in: Regenerate.
	* libbacktrace/Makefile.am: Update AM_CFLAGS, AM_CXXFLAGS.
	* libbacktrace/Makefile.in: Regenerate.
	* lsan/Makefile.am: Update AM_CXXFLAGS.
	* lsan/Makefile.in: Regenerate.
	* sanitizer_common/Makefile.am: Update AM_CXXFLAGS,
	AM_CCASFLAGS.
	* sanitizer_common/sanitizer_linux_x86_64.S: Include cet.h.
	Add _CET_ENDBR macro.
	* sanitizer_common/Makefile.in: Regenerate.
	* tsan/Makefile.am: Update AM_CXXFLAGS.
	* tsan/Makefile.in: Regenerate.
	* tsan/tsan_rtl_amd64.S Include cet.h. Add _CET_ENDBR macro.
	* ubsan/Makefile.am: Update AM_CXXFLAGS.
	* ubsan/Makefile.in: Regenerate.

From-SVN: r254896