Address review feedback

Author: cyndyishida

clang/lib/Serialization/ASTReader.cpp

@@ -5834,12 +5834,13 @@ bool ASTReader::readASTFileControlBlock(
           break;
         case INPUT_FILE:
           bool Overridden = static_cast<bool>(Record[3]);
-          size_t FilenameLen = ModuleDir.size() + Record[7] + 1;
-          auto Filename = ResolveImportedPath(PathBuf, Blob, ModuleDir);
-          StringRef FilenameAsRequested = Filename->substr(0, FilenameLen);
-          StringRef ExternalFilename = Filename->substr(FilenameLen);
+          const size_t FilenameAsRequestedLength = Record[7] + 1;
+          auto ResolvedFilenameAsRequested = ResolveImportedPath(
+              PathBuf, Blob.substr(0, FilenameAsRequestedLength), ModuleDir);
+          StringRef ExternalFilename = Blob.substr(FilenameAsRequestedLength);
           shouldContinue = Listener.visitInputFile(
-              FilenameAsRequested, ExternalFilename, isSystemFile, Overridden,
+              ResolvedFilenameAsRequested->str(), ExternalFilename,
+              isSystemFile, Overridden,
               /*IsExplicitModule=*/false);
           break;
         }

clang/test/ClangScanDeps/prebuilt-modules-in-stable-dirs.c

@@ -2,7 +2,7 @@
 ///   resolve `is-in-stable-directories` correctly. 
 /// The steps are: 
 /// 1. Scan dependencies to build the PCH. One of the module's depend on header 
-///   that is seemingly from the sysroot. However, it depends on a local header that is overlaid.. 
+///   that is seemingly from the sysroot. However, it depends on a local header that is overlaid.
 /// 2. Build the PCH & dependency PCMs.
 /// 3. Scan a source file that transitively depends on the same modules as the pcm.