[flang] Rename remaining `__Fortran_PPC_intrinsics` to `__ppc_intrinsics`

[sunshaoce]

Rebased

[kkwli0]

Good catch. Thanks. LGTM

[sunshaoce]

Thanks! The patch has landed on https://github.com/llvm/llvm-project/commit/db8e902b30d22528f0d72918eb46f141b73c8116

flang/include/flang/Semantics/semantics.h

private:
   };
   std::map<SymbolRef, const IndexVarInfo, SymbolAddressCompare>
       activeIndexVars_;
   UnorderedSymbolSet errorSymbols_;
   std::set<std::string> tempNames_;
   const Scope *builtinsScope_{nullptr}; // module __Fortran_builtins
   Scope *ppcBuiltinTypesScope_{nullptr}; // module __Fortran_PPC_types
   std::optional<const Scope *> cudaBuiltinsScope_; // module __CUDA_builtins
-  const Scope *ppcBuiltinsScope_{nullptr}; // module __Fortran_PPC_intrinsics
+  const Scope *ppcBuiltinsScope_{nullptr}; // module __ppc_intrinsics
   std::list<parser::Program> modFileParseTrees_;
   std::unique_ptr<CommonBlockMap> commonBlockMap_;
   bool anyDefinedIntrinsicOperator_{false};
 };
 
 class Semantics {
 public:
   explicit Semantics(SemanticsContext &context, parser::Program &program,

flang/lib/Semantics/semantics.cpp

if (frontModule &&
         (std::get<parser::Statement<parser::ModuleStmt>>(frontModule->value().t)
                     .statement.v.source == "__fortran_builtins" ||
             std::get<parser::Statement<parser::ModuleStmt>>(
                 frontModule->value().t)
                     .statement.v.source == "__ppc_types")) {
       // Don't try to read the builtins module when we're actually building it.
     } else if (frontModule &&
         std::get<parser::Statement<parser::ModuleStmt>>(frontModule->value().t)
-                .statement.v.source == "__fortran_ppc_intrinsics") {
+                .statement.v.source == "__ppc_intrinsics") {
       // The derived type definition for the vectors is needed.
       context_.UsePPCBuiltinTypesModule();
     } else {
       context_.UseFortranBuiltinsModule();
       llvm::Triple targetTriple{llvm::Triple(
           llvm::Triple::normalize(llvm::sys::getDefaultTargetTriple()))};
       // Only use __ppc_intrinsics module when targetting PowerPC arch
       if (context_.targetCharacteristics().isPPC()) {