[clang] [clang][deps] Load module map file from PCM (PR #66389)

[Ben Langmuir via cfe-commits]

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@@ -482,16 +482,9 @@ ModuleDepCollectorPP::handleTopLevelModule(const Module *M) {
   MD.ID.ModuleName = M->getFullModuleName();
   MD.IsSystem = M->IsSystem;
 
-  ModuleMap &ModMapInfo =
-      MDC.ScanInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
-
-  OptionalFileEntryRef ModuleMap = ModMapInfo.getModuleMapFileForUniquing(M);
-
-  if (ModuleMap) {
-    SmallString<128> Path = ModuleMap->getNameAsRequested();
-    ModMapInfo.canonicalizeModuleMapPath(Path);
-    MD.ClangModuleMapFile = std::string(Path);
-  }
+  assert(!M->PresumedModuleMapFile.empty() &&
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benlangmuir wrote:

There's a comment in Module.h: `/// Only non-empty when building from preprocessed source.` that should probably be deleted.

https://github.com/llvm/llvm-project/pull/66389