[NFC] Remove duplicate isNoBuiltinFunc method

[serge-sans-paille]

Summary

It's available both in CodeGenOptions and in LangOptions, and LangOptions
implementation is slightly better as it uses a StringRef instead of a char
pointer, so use it.

[mehdi_amini]

Seems like NFC? Can you tag the title with it?

[serge-sans-paille]

Well, it's not exactly a non functional change as it changes the API. A downstream user may need to update its code after this commit, right?

[mehdi_amini]

In D98175#2613044, @serge-sans-paille wrote:

Well, it's not exactly a non functional change as it changes the API. A downstream user may need to update its code after this commit, right?

That's true for every refactoring: in general my rule of thumb is that if it isn't NFC there should be a test :)

[serge-sans-paille]

That was a very convincing argument :-) tag added.

clang/include/clang/Basic/CodeGenOptions.h

 #define CODEGENOPT(Name, Bits, Default)
 #define ENUM_CODEGENOPT(Name, Type, Bits, Default) \
   Type get##Name() const { return static_cast<Type>(Name); } \
   void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
 #include "clang/Basic/CodeGenOptions.def"
 
   CodeGenOptions();
 
-  /// Is this a libc/libm function that is no longer recognized as a
-  /// builtin because a -fno-builtin-* option has been specified?
-  bool isNoBuiltinFunc(const char *Name) const;
-
   const std::vector<std::string> &getNoBuiltinFuncs() const {
     return NoBuiltinFuncs;
   }
 
   /// Check if Clang profile instrumenation is on.
   bool hasProfileClangInstr() const {
     return getProfileInstr() == ProfileClangInstr;
   }

clang/lib/Basic/CodeGenOptions.cpp

 #define CODEGENOPT(Name, Bits, Default) Name = Default;
 #define ENUM_CODEGENOPT(Name, Type, Bits, Default) set##Name(Default);
 #include "clang/Basic/CodeGenOptions.def"
 
   RelocationModel = llvm::Reloc::PIC_;
   memcpy(CoverageVersion, "408*", 4);
 }
 
-bool CodeGenOptions::isNoBuiltinFunc(const char *Name) const {
-  StringRef FuncName(Name);
-  for (unsigned i = 0, e = NoBuiltinFuncs.size(); i != e; ++i)
-    if (FuncName.equals(NoBuiltinFuncs[i]))
-      return true;
-  return false;
-}
-
 }  // end namespace clang

clang/lib/CodeGen/CGCall.cpp

if (CodeGenOpts.DisableRedZone)
     FuncAttrs.addAttribute(llvm::Attribute::NoRedZone);
   if (CodeGenOpts.IndirectTlsSegRefs)
     FuncAttrs.addAttribute("indirect-tls-seg-refs");
   if (CodeGenOpts.NoImplicitFloat)
     FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat);
 
   if (AttrOnCallSite) {
     // Attributes that should go on the call site only.
-    if (!CodeGenOpts.SimplifyLibCalls ||
-        CodeGenOpts.isNoBuiltinFunc(Name.data()))
+    if (!CodeGenOpts.SimplifyLibCalls || LangOpts.isNoBuiltinFunc(Name))
       FuncAttrs.addAttribute(llvm::Attribute::NoBuiltin);
     if (!CodeGenOpts.TrapFuncName.empty())
       FuncAttrs.addAttribute("trap-func-name", CodeGenOpts.TrapFuncName);
   } else {
     StringRef FpKind;
     switch (CodeGenOpts.getFramePointer()) {
     case CodeGenOptions::FramePointerKind::None:
       FpKind = "none";