[clang] [clang-tools-extra] [llvm] [clang] Introduce diagnostics suppression mappings (PR #112517)

[Boaz Brickner via cfe-commits]

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@@ -70,6 +76,16 @@ void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
   else
     Diags.setExtensionHandlingBehavior(diag::Severity::Ignored);
 
+  if (!Opts.DiagnosticSuppressionMappingsFile.empty()) {
+    if (auto Buf =
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bricknerb wrote:

This is typically called File and sometimes called FileOrError

https://github.com/llvm/llvm-project/pull/112517