[binutils-gdb] x86-64: Also optimize "clr reg64"

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT d3d50934a9101416c3106497d6ea9ce548760253 ***

Author: H.J. Lu <hjl.tools@gmail.com>
Branch: master
Commit: d3d50934a9101416c3106497d6ea9ce548760253

x86-64: Also optimize "clr reg64"

"clr reg" is an alias of "xor reg, reg".  We can encode "clr reg64" as
"xor reg32, reg32".

gas/

	* config/tc-i386.c (optimize_encoding): Also encode "clr reg64"
	as "xor reg32, reg32".
	* testsuite/gas/i386/x86-64-optimize-1.s: Add "clr reg64" tests.
	* testsuite/gas/i386/x86-64-optimize-1.d: Updated.

opcodes/

	* i386-opc.tbl: Add Optimize to clr.
	* i386-tbl.h: Regenerated.