[llvm] [Dexter] Fix test failures on greendragon (PR #66299)

[Stephen Tozer via llvm-commits]

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@@ -217,6 +218,9 @@ def _run_test(self, test_name):
         """
         try:
             if self.context.options.binary:
+                if platform.system() == 'Darwin' and os.path.exists(self.context.options.binary + '.dSYM'):
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SLTozer wrote:

Might be a good idea to add a command line option to manually specify the location of the dsym file, but I'm happy to submit that as an extra patch afterwards.

https://github.com/llvm/llvm-project/pull/66299