[test] Skip a test when using an out-of-tree debugserver
The test "test_fp_special_purpose_register_read" in TestRegisters.py
fails on Darwin machines configured to use an out-of-tree debugserver.
The error message is: 'register read ftag' returns expected result, got
'ftag = 0x80'. This indicates that the debugserver in use is too old.
This commit introduces a decorator which can be used to skip tests which
rely on having a just-built debugserver. This resolves the issue:
$ ./bin/llvm-dotest -p TestRegisters.py -v
1 out of 617 test suites processed - TestRegisters.py
Test Methods: 7
Success: 6
Skip: 1
...
llvm-svn: 327052