[clang][parse] NFCI: Use FileEntryRef in Parser::ParseModuleImport()

[jansvoboda11]

Summary

This patch removes use of the deprecated DirectoryEntry::getName() from Parser by using {File,Directory}EntryRef instead.

[bnbarham]

Thanks for doing all these Jan!

clang/lib/Parse/Parser.cpp

Decl *Parser::ParseModuleImport(SourceLocation AtLoc,
   ExpectAndConsumeSemi(diag::err_module_expected_semi);
   if (Import.isInvalid())
     return nullptr;
 
   // Using '@import' in framework headers requires modules to be enabled so that
   // the header is parseable. Emit a warning to make the user aware.
   if (IsObjCAtImport && AtLoc.isValid()) {
     auto &SrcMgr = PP.getSourceManager();
-    auto *FE = SrcMgr.getFileEntryForID(SrcMgr.getFileID(AtLoc));
-    if (FE && llvm::sys::path::parent_path(FE->getDir()->getName())
+    auto FE = SrcMgr.getFileEntryRefForID(SrcMgr.getFileID(AtLoc));
+    if (FE && llvm::sys::path::parent_path(FE->getDir().getName())
                   .endswith(".framework"))
       Diags.Report(AtLoc, diag::warn_atimport_in_framework_header);
   }
 
   return Import.get();
 }
 
 /// Parse a C++ Modules TS / Objective-C module name (both forms use the same