Remove `Sema::getFloat128Identifier`

[davidstone]

Summary

This function was added prior to clang supporting __float128 to ensure clang could compile a libstdc++ header. This is no longer used or needed now that clang actually supports __float128.

clang/include/clang/Sema/Sema.h

private:
   void CheckAddressOfPackedMember(Expr *rhs);
 
   /// The parser's current scope.
   ///
   /// The parser maintains this state here.
   Scope *CurScope;
 
   mutable IdentifierInfo *Ident_super;
-  mutable IdentifierInfo *Ident___float128;
 
   /// Nullability type specifiers.
   IdentifierInfo *Ident__Nonnull = nullptr;
   IdentifierInfo *Ident__Nullable = nullptr;
   IdentifierInfo *Ident__Nullable_result = nullptr;
   IdentifierInfo *Ident__Null_unspecified = nullptr;
 
   IdentifierInfo *Ident_NSError = nullptr;
public:
   /// template substitution or instantiation.
   Scope *getCurScope() const { return CurScope; }
 
   void incrementMSManglingNumber() const {
     return CurScope->incrementMSManglingNumber();
   }
 
   IdentifierInfo *getSuperIdentifier() const;
-  IdentifierInfo *getFloat128Identifier() const;
 
   ObjCContainerDecl *getObjCDeclContext() const;
 
   DeclContext *getCurLexicalContext() const {
     return OriginalLexicalContext ? OriginalLexicalContext : CurContext;
   }
 
   const DeclContext *getCurObjCLexicalContext() const {

clang/lib/Sema/Sema.cpp

: ExternalSource(nullptr), CurFPFeatures(pp.getLangOpts()),
       VtorDispStack(LangOpts.getVtorDispMode()),
       AlignPackStack(AlignPackInfo(getLangOpts().XLPragmaPack)),
       DataSegStack(nullptr), BSSSegStack(nullptr), ConstSegStack(nullptr),
       CodeSegStack(nullptr), StrictGuardStackCheckStack(false),
       FpPragmaStack(FPOptionsOverride()), CurInitSeg(nullptr),
       VisContext(nullptr), PragmaAttributeCurrentTargetDecl(nullptr),
       IsBuildingRecoveryCallExpr(false), LateTemplateParser(nullptr),
       LateTemplateParserCleanup(nullptr), OpaqueParser(nullptr), IdResolver(pp),
-      StdInitializerList(nullptr),
-      StdCoroutineTraitsCache(nullptr), CXXTypeInfoDecl(nullptr),
-      MSVCGuidDecl(nullptr), StdSourceLocationImplDecl(nullptr),
-      NSNumberDecl(nullptr), NSValueDecl(nullptr), NSStringDecl(nullptr),
+      StdInitializerList(nullptr), StdCoroutineTraitsCache(nullptr),
+      CXXTypeInfoDecl(nullptr), MSVCGuidDecl(nullptr),
+      StdSourceLocationImplDecl(nullptr), NSNumberDecl(nullptr),
+      NSValueDecl(nullptr), NSStringDecl(nullptr),
       StringWithUTF8StringMethod(nullptr),
       ValueWithBytesObjCTypeMethod(nullptr), NSArrayDecl(nullptr),
       ArrayWithObjectsMethod(nullptr), NSDictionaryDecl(nullptr),
       DictionaryWithObjectsMethod(nullptr), GlobalNewDeleteDeclared(false),
       TUKind(TUKind), NumSFINAEErrors(0),
       FullyCheckedComparisonCategories(
           static_cast<unsigned>(ComparisonCategoryType::Last) + 1),
       SatisfactionCache(Context), AccessCheckingSFINAE(false),
       InNonInstantiationSFINAEContext(false), NonInstantiationEntries(0),
       ArgumentPackSubstitutionIndex(-1), CurrentInstantiationScope(nullptr),
       DisableTypoCorrection(false), TyposCorrected(0), AnalysisWarnings(*this),
       ThreadSafetyDeclCache(nullptr), VarDataSharingAttributesStack(nullptr),
-      CurScope(nullptr), Ident_super(nullptr), Ident___float128(nullptr) {
+      CurScope(nullptr), Ident_super(nullptr) {
   assert(pp.TUKind == TUKind);
   TUScope = nullptr;
   isConstantEvaluatedOverride = false;
 
   LoadedExternalKnownNamespaces = false;
   for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
     NSNumberLiteralMethods[I] = nullptr;
 

 }
 
 IdentifierInfo *Sema::getSuperIdentifier() const {
   if (!Ident_super)
     Ident_super = &Context.Idents.get("super");
   return Ident_super;
 }
 
-IdentifierInfo *Sema::getFloat128Identifier() const {
-  if (!Ident___float128)
-    Ident___float128 = &Context.Idents.get("__float128");
-  return Ident___float128;
-}
-
 void Sema::PushCapturedRegionScope(Scope *S, CapturedDecl *CD, RecordDecl *RD,
                                    CapturedRegionKind K,
                                    unsigned OpenMPCaptureLevel) {
   auto *CSI = new CapturedRegionScopeInfo(
       getDiagnostics(), S, CD, RD, CD->getContextParam(), K,
       (getLangOpts().OpenMP && K == CR_OpenMP) ? getOpenMPNestingLevel() : 0,
       OpenMPCaptureLevel);
   CSI->ReturnType = Context.VoidTy;