Merge commit '52dd5edd5424' from apple/stable/20200108 into swift/release/5.3

Author: git apple-llvm automerger

lldb/packages/Python/lldbsuite/test/decorators.py

@@ -552,6 +552,16 @@ def are_sb_headers_missing():
     return skipTestIfFn(are_sb_headers_missing)(func)
 
 
+def skipIfRosetta(bugnumber):
+    """Skip a test when running the testsuite on macOS under the Rosetta translation layer."""
+    def is_running_rosetta(self):
+        if not lldbplatformutil.getPlatform() in ['darwin', 'macosx']:
+            return "not on macOS"
+        if (platform.uname()[5] == "arm") and (self.getArchitecture() == "x86_64"):
+            return "skipped under Rosetta"
+        return None
+    return skipTestIfFn(is_running_rosetta)
+
 def skipIfiOSSimulator(func):
     """Decorate the item to skip tests that should be skipped on the iOS Simulator."""
     def is_ios_simulator():