Frontend: Migrate to FileEntryRef in VerifyDiagnosticConsumer.cpp, NFC

[dexonsmith]

Summary

Add a FileEntryRef overload of SourceManager::translateFile, and
migrate ParseDirective in VerifyDiagnosticConsumer.cpp to use it and
the corresponding overload of createFileID.

No functionality change here.

[jansvoboda11]

LGTM.

clang/include/clang/Basic/SourceManager.h

public:
   SourceLocation translateFileLineCol(const FileEntry *SourceFile,
                                       unsigned Line, unsigned Col) const;
 
   /// Get the FileID for the given file.
   ///
   /// If the source file is included multiple times, the FileID will be the
   /// first inclusion.
   FileID translateFile(const FileEntry *SourceFile) const;
+  FileID translateFile(FileEntryRef SourceFile) const {
+    return translateFile(&SourceFile.getFileEntry());
+  }
 
   /// Get the source location in \p FID for the given line:col.
   /// Returns null location if \p FID is not a file SLocEntry.
   SourceLocation translateLineCol(FileID FID,
                                   unsigned Line, unsigned Col) const;
 
   /// If \p Loc points inside a function macro argument, the returned
   /// location will be the macro location in which the argument was expanded.

clang/lib/Frontend/VerifyDiagnosticConsumer.cpp

if (!PH.Next("@")) {
                              nullptr, nullptr, nullptr, nullptr, nullptr);
           if (!File) {
             Diags.Report(Pos.getLocWithOffset(PH.C - PH.Begin),
                          diag::err_verify_missing_file)
                 << Filename << KindStr;
             continue;
           }
 
-          const FileEntry *FE = &File->getFileEntry();
-          FileID FID = SM.translateFile(FE);
+          FileID FID = SM.translateFile(*File);
           if (FID.isInvalid())
-            FID = SM.createFileID(FE, Pos, SrcMgr::C_User);
+            FID = SM.createFileID(*File, Pos, SrcMgr::C_User);
 
           if (PH.Next(Line) && Line > 0)
             ExpectedLoc = SM.translateLineCol(FID, Line, 1);
           else if (PH.Next("*")) {
             MatchAnyLine = true;
             ExpectedLoc = SM.translateLineCol(FID, 1, 1);
           }
         }