GDB PowerPC record test cases for ISA 2.06 and ISA 3.1

This patch adds PowerPC specific tests to verify recording of various
instructions.  The first test case checks the ISA 2.06 lxvd2x instruction.
The second test case tests several of the ISA 3.01 instructions.  Specifically,
it checks the word and prefixed instructions and some of the Matrix
Multiply Assist (MMA) instructions.

The patch has been run on both Power 10 and Power 9 to verify the ISA
2.06 test case runs on both platforms without errors.  The ISA 3.1 test
runs without errors on Power 10 and is skipped as expected on Power 9.