[clang] [libc++][lit] Allow overriding the executor for tests (PR #66545)

[Alexander Richardson via cfe-commits]

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@@ -330,5 +330,14 @@ def getModuleFlag(cfg, enable_modules):
             AddCompileFlag("-D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES"),
         ],
     ),
+    Parameter(
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arichardson wrote:

Done now, tested both the default and the case where LIBCXX_EXECUTOR is set. Hope this works as expected for all CI configurations.

https://github.com/llvm/llvm-project/pull/66545