[clang] [clang][modulemap] Lazily load module maps by header name (PR #181916)

[Jan Svoboda via cfe-commits]

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@@ -435,6 +435,18 @@ class ModuleMap {
   KnownHeader findModuleForHeader(FileEntryRef File, bool AllowTextual = false,
                                   bool AllowExcluded = false);
 
+  /// Find the FileEntry for a header in a module as if it was written in the
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jansvoboda11 wrote:

```suggestion
  /// Find the FileEntry for an umbrella header in a module as if it was written in the
```

https://github.com/llvm/llvm-project/pull/181916