Since only the first 32 bits of input operand are used for tpause and
umwait, the REX.W bit is skipped.  Both 32-bit registers and 64-bit
registers are allowed.

gas/

	* testsuite/gas/i386/x86-64-waitpkg.s: Add 32-bit registers
	tests for tpause and umwait.
	* testsuite/gas/i386/x86-64-waitpkg-intel.d: Updated.
	* testsuite/gas/i386/x86-64-waitpkg.d: Likewise.

opcodes/

	* i386-dis.c (prefix_table): Replace Em with Edq on tpause and
	umwait.
	* i386-opc.tbl: Allow 32-bit registers for tpause and umwait in
	64-bit mode.
	* i386-tbl.h: Regenerated.