Revert "[NFC] Explicitly pass a VFS when creating DiagnosticsEngine (#115852)"

Reverted for causing:
#117145

This reverts commit bdd10d9.

Author: sylvestre

clang-tools-extra/clang-include-fixer/IncludeFixer.cpp

@@ -95,8 +95,7 @@ bool IncludeFixerActionFactory::runInvocation(
 
   // Create the compiler's actual diagnostics engine. We want to drop all
   // diagnostics here.
-  Compiler.createDiagnostics(Files->getVirtualFileSystem(),
-                             new clang::IgnoringDiagConsumer,
+  Compiler.createDiagnostics(new clang::IgnoringDiagConsumer,
                              /*ShouldOwnClient=*/true);
   Compiler.createSourceManager(*Files);
 

clang-tools-extra/clangd/Compiler.cpp

@@ -110,8 +110,8 @@ buildCompilerInvocation(const ParseInputs &Inputs, clang::DiagnosticConsumer &D,
   CIOpts.VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   CIOpts.CC1Args = CC1Args;
   CIOpts.RecoverOnError = true;
-  CIOpts.Diags = CompilerInstance::createDiagnostics(
-      *CIOpts.VFS, new DiagnosticOptions, &D, false);
+  CIOpts.Diags =
+      CompilerInstance::createDiagnostics(new DiagnosticOptions, &D, false);
   CIOpts.ProbePrecompiled = false;
   std::unique_ptr<CompilerInvocation> CI = createInvocation(ArgStrs, CIOpts);
   if (!CI)
@@ -148,7 +148,7 @@ prepareCompilerInstance(std::unique_ptr<clang::CompilerInvocation> CI,
   auto Clang = std::make_unique<CompilerInstance>(
       std::make_shared<PCHContainerOperations>());
   Clang->setInvocation(std::move(CI));
-  Clang->createDiagnostics(*VFS, &DiagsClient, false);
+  Clang->createDiagnostics(&DiagsClient, false);
 
   if (auto VFSWithRemapping = createVFSFromCompilerInvocation(
           Clang->getInvocation(), Clang->getDiagnostics(), VFS))