[clang] [llvm] Reland "[Utils] Add new --update-tests flag to llvm-lit" (PR #153821)

[Min-Yih Hsu via cfe-commits]

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@@ -399,6 +399,11 @@ ADDITIONAL OPTIONS
  Show all features used in the test suite (in ``XFAIL``, ``UNSUPPORTED`` and
  ``REQUIRES``) and exit.
 
+.. option:: --update-tests
+
+ Pass failing tests to functions in the ``lit_config.update_tests`` list to
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mshockwave wrote:

do you mean "to functions in the `list_config.test_updaters` list"? `lit_config.update_tests` is a boolean value.

https://github.com/llvm/llvm-project/pull/153821