MIPS/GAS/testsuite: Add tests for coprocessor branch instructions

Cover basic CP0, CP2, CP3 branch and branch-likely instructions across
the relevant ISA levels.  Omit CP1 branches, covered elsewhere.

	gas/
	* testsuite/gas/mips/cp0b.d: New test.
	* testsuite/gas/mips/cp0bl.d: New test.
	* testsuite/gas/mips/cp2b.d: New test.
	* testsuite/gas/mips/micromips@cp2b.d: New test.
	* testsuite/gas/mips/cp2bl.d: New test.
	* testsuite/gas/mips/micromips@cp2bl.d: New test.
	* testsuite/gas/mips/cp3b.d: New test.
	* testsuite/gas/mips/cp3bl.d: New test.
	* testsuite/gas/mips/cp0b.s: New test source.
	* testsuite/gas/mips/cp0bl.s: New test source.
	* testsuite/gas/mips/cp2b.s: New test source.
	* testsuite/gas/mips/cp2bl.s: New test source.
	* testsuite/gas/mips/cp3b.s: New test source.
	* testsuite/gas/mips/cp3bl.s: New test source.
	* testsuite/gas/mips/mips.exp: Run the new tests.
16 files changed