Remove unused clang::TargetInfo::adjustTargetOptions

The hook introduced by https://reviews.llvm.org/D22815 for AMDGPU was
removed by commit ce2258c in 2020.

Author: MaskRay

clang/include/clang/Basic/TargetInfo.h

@@ -1260,10 +1260,6 @@ class TargetInfo : public TransferrableTargetInfo,
   /// the language based on the target options where applicable.
   virtual void adjust(DiagnosticsEngine &Diags, LangOptions &Opts);
 
-  /// Adjust target options based on codegen options.
-  virtual void adjustTargetOptions(const CodeGenOptions &CGOpts,
-                                   TargetOptions &TargetOpts) const {}
-
   /// Initialize the map with the default set of target features for the
   /// CPU this should include all legal feature strings on the target.
   ///

clang/lib/Frontend/CompilerInstance.cpp

@@ -151,9 +151,6 @@ bool CompilerInstance::createTarget() {
   // created. This complexity should be lifted elsewhere.
   getTarget().adjust(getDiagnostics(), getLangOpts());
 
-  // Adjust target options based on codegen options.
-  getTarget().adjustTargetOptions(getCodeGenOpts(), getTargetOpts());
-
   if (auto *Aux = getAuxTarget())
     getTarget().setAuxTarget(Aux);