s390: Position independent verification of relative addressing

s390: Position independent verification of relative addressing

Opcode test cases for z/Architecture instructions that use relative
addressing contained hardcoded offsets in the test verification
patterns. Inserting or reordering of instructions into those test cases
therefore required updating of those hardcoded offsets.

Use regular expressions with backreferences to verify results of test
cases containing instructions with relative addressing. This makes the
verification position independent.

gas/
	* testsuite/gas/s390/esa-g5.d: Make opcode test verification
	  pattern position independent where possible.
	* testsuite/gas/s390/esa-z900.d: Likewise.
	* testsuite/gas/s390/zarch-z900.d: Likewise.
	* testsuite/gas/s390/zarch-z10.d: Likewise.
	* testsuite/gas/s390/zarch-z196.d: Likewise.
	* testsuite/gas/s390/zarch-zEC12.d: Likewise.

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Andreas Krebbel <krebbel@linux.ibm.com>