x86: Check register operand for AddrPrefixOpReg

x86: Check register operand for AddrPrefixOpReg

If the address prefix changes the register operand, we need to check the
register operand when the memory operand is RIP-relative.

	PR gas/26685
	* config/tc-i386.c (process_suffix): Check the register operand
	for the address size prefix if the memory operand is symbol(%rip).
	* testsuite/gas/i386/x86-64-enqcmd.s: Add tests with RIP-relative
	addressing.
	* testsuite/gas/i386/x86-64-movdir.s: Likewise.
	* testsuite/gas/i386/x86-64-enqcmd-intel.d: Updated.
	* testsuite/gas/i386/x86-64-enqcmd.d: Likewise.
	* testsuite/gas/i386/x86-64-movdir-intel.d: Likewise.
	* testsuite/gas/i386/x86-64-movdir.d: Likewise.