* gas-test.scm (gen-gas-test): Create 8 testcases, not just 5.
(<operand> 'test-data): Involve both the index and the hardware
in testcase generation.
(<hw-indx> 'test-data): Generate test data from the underlying
object.
(<ifield> 'test-data): Generate test data by computing bit
patterns for the field, then decoding them.
(<hw-address> 'test-data): Allow for new calling convention.
(<hw-iaddress> 'test-data): Likewise.
(<keyword> 'test-data): Convert index values into keywords.
(<hw-asm> 'test-data): Convert index values into integer strings.