[clang] [clang] Make SARIF better handle diagnostic about unknown argument (PR #233241)

[Kazu Hirata via cfe-commits]

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@@ -65,6 +65,13 @@
 
 // IGNORED: warning: unknown warning option '-Wunknown-to-clang-option'
 
+// RUN %clang -fdiagnostics-format=sarif -Wunknown-to-clang-option
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kazutakahirata wrote:

Do you mean to say `RUN:` with a colon and pass `-S %s -o %t.s` here so that you can verify that `%clang` at least accepts the option without crashing even though we cannot check the diagnostic output yet?
```suggestion
// RUN: %clang -S %s -o %t.s -fdiagnostics-format=sarif -Wunknown-to-clang-option
```


https://github.com/llvm/llvm-project/pull/233241