[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

1 files changed, 3 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/dotest.py b/lldb/packages/Python/lldbsuite/test/dotest.py
index 800a60e6891..41a15ebe12b 100644
--- a/lldb/packages/Python/lldbsuite/test/dotest.py
+++ b/lldb/packages/Python/lldbsuite/test/dotest.py
@@ -307,6 +307,9 @@ def parseOptionsAndInitTestdirs():
     if args.log_success:
         lldbtest_config.log_success = args.log_success
 
+    if args.out_of_tree_debugserver:
+        lldbtest_config.out_of_tree_debugserver = args.out_of_tree_debugserver
+
     # Set SDKROOT if we are using an Apple SDK
     if platform_system == 'Darwin' and args.apple_sdk:
         os.environ['SDKROOT'] = seven.get_command_output(