Allow memory operands for PTWRITE

The earlier PTWRITE builtin definition was unnecessarily restrictive,
only allowing register input to PTWRITE. The instruction actually
supports memory operands too, so allow that too.

gcc/:

2018-11-16  Andi Kleen  <ak@linux.intel.com>

	* config/i386/i386.md: Allow memory operands to ptwrite.

From-SVN: r266211

gcc/ChangeLog

+2018-11-16  Andi Kleen  <ak@linux.intel.com>
+
+	* config/i386/i386.md: Allow memory operands to ptwrite.
+
 2018-11-16  Michael Matz  <matz@suse.de>
 
 	* system.h (PRsa): New macro.

gcc/config/i386/i386.md

@@ -19501,7 +19501,7 @@
    (set_attr "prefix_extra" "2")])
 
 (define_insn "ptwrite<mode>"
-  [(unspec_volatile [(match_operand:SWI48 0 "register_operand" "r")]
+  [(unspec_volatile [(match_operand:SWI48 0 "nonimmediate_operand" "rm")]
 		    UNSPECV_PTWRITE)]
   "TARGET_PTWRITE"
   "ptwrite\t%0"