Improve const-correctness. NFC.

clang/include/clang/Lex/MacroInfo.h

@@ -521,7 +521,7 @@ public:
   }
 
   static void Profile(llvm::FoldingSetNodeID &ID, Module *OwningModule,
-                      IdentifierInfo *II) {
+                      const IdentifierInfo *II) {
     ID.AddPointer(OwningModule);
     ID.AddPointer(II);
   }

clang/include/clang/Lex/Preprocessor.h

@@ -1151,7 +1151,7 @@ public:
   /// Register an exported macro for a module and identifier.
   ModuleMacro *addModuleMacro(Module *Mod, IdentifierInfo *II, MacroInfo *Macro,
                               ArrayRef<ModuleMacro *> Overrides, bool &IsNew);
-  ModuleMacro *getModuleMacro(Module *Mod, IdentifierInfo *II);
+  ModuleMacro *getModuleMacro(Module *Mod, const IdentifierInfo *II);
 
   /// Get the list of leaf (non-overridden) module macros for a name.
   ArrayRef<ModuleMacro*> getLeafModuleMacros(const IdentifierInfo *II) const {

clang/lib/Lex/PPDirectives.cpp

@@ -124,7 +124,7 @@ static bool isReservedId(StringRef Text, const LangOptions &Lang) {
 // the specified module, meaning clang won't build the specified module. This is
 // useful in a number of situations, for instance, when building a library that
 // vends a module map, one might want to avoid hitting intermediate build
-// products containimg the the module map or avoid finding the system installed
+// products containing the the module map or avoid finding the system installed
 // modulemap for that library.
 static bool isForModuleBuilding(Module *M, StringRef CurrentModule,
                                 StringRef ModuleName) {

clang/lib/Lex/PPMacroExpansion.cpp

@@ -170,7 +170,8 @@ ModuleMacro *Preprocessor::addModuleMacro(Module *Mod, IdentifierInfo *II,
   return MM;
 }
 
-ModuleMacro *Preprocessor::getModuleMacro(Module *Mod, IdentifierInfo *II) {
+ModuleMacro *Preprocessor::getModuleMacro(Module *Mod,
+                                          const IdentifierInfo *II) {
   llvm::FoldingSetNodeID ID;
   ModuleMacro::Profile(ID, Mod, II);