MIPS/GAS/testsuite: Convert branch local list tests to dump tests
gas/
* testsuite/gas/mips/branch-local-2.d: New test.
* testsuite/gas/mips/branch-local-3.d: New test.
* testsuite/gas/mips/branch-local-n32-2.d: New test.
* testsuite/gas/mips/branch-local-n32-3.d: New test.
* testsuite/gas/mips/branch-local-n64-2.d: New test.
* testsuite/gas/mips/branch-local-n64-3.d: New test.
* testsuite/gas/mips/mips.exp: Fold corresponding list tests
into the new tests.