Sync with GCC
	2018-04-05  H.J. Lu  <hongjiu.lu@intel.com>

	PR gas/22318
	* plugins.m4 (AC_PLUGINS): Use dlsym to check if libdl is needed.

	2018-02-14  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>

	PR target/84148
	* cet.m4: Check if target support multi-byte NOPS (SSE).