[clang][AST][NFC] Make ASTContext::UnwrapSimilar{Array,}Types const (#106992)

They don't mutate the context at all, so mark them const.

Author: tbaederr

clang/include/clang/AST/ASTContext.h

@@ -2722,9 +2722,9 @@ class ASTContext : public RefCountedBase<ASTContext> {
                            const ObjCMethodDecl *MethodImp);
 
   bool UnwrapSimilarTypes(QualType &T1, QualType &T2,
-                          bool AllowPiMismatch = true);
+                          bool AllowPiMismatch = true) const;
   void UnwrapSimilarArrayTypes(QualType &T1, QualType &T2,
-                               bool AllowPiMismatch = true);
+                               bool AllowPiMismatch = true) const;
 
   /// Determine if two types are similar, according to the C++ rules. That is,
   /// determine if they are the same other than qualifiers on the initial
@@ -2733,7 +2733,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
   ///
   /// Clang offers a number of qualifiers in addition to the C++ qualifiers;
   /// those qualifiers are also ignored in the 'similarity' check.
-  bool hasSimilarType(QualType T1, QualType T2);
+  bool hasSimilarType(QualType T1, QualType T2) const;
 
   /// Determine if two types are similar, ignoring only CVR qualifiers.
   bool hasCvrSimilarType(QualType T1, QualType T2);

clang/lib/AST/ASTContext.cpp

@@ -6581,7 +6581,7 @@ QualType ASTContext::getUnqualifiedArrayType(QualType type,
 /// \param AllowPiMismatch Allow the Pi1 and Pi2 to differ as described in
 ///        C++20 [conv.qual], if permitted by the current language mode.
 void ASTContext::UnwrapSimilarArrayTypes(QualType &T1, QualType &T2,
-                                         bool AllowPiMismatch) {
+                                         bool AllowPiMismatch) const {
   while (true) {
     auto *AT1 = getAsArrayType(T1);
     if (!AT1)
@@ -6632,7 +6632,7 @@ void ASTContext::UnwrapSimilarArrayTypes(QualType &T1, QualType &T2,
 /// \return \c true if a pointer type was unwrapped, \c false if we reached a
 /// pair of types that can't be unwrapped further.
 bool ASTContext::UnwrapSimilarTypes(QualType &T1, QualType &T2,
-                                    bool AllowPiMismatch) {
+                                    bool AllowPiMismatch) const {
   UnwrapSimilarArrayTypes(T1, T2, AllowPiMismatch);
 
   const auto *T1PtrType = T1->getAs<PointerType>();
@@ -6668,7 +6668,7 @@ bool ASTContext::UnwrapSimilarTypes(QualType &T1, QualType &T2,
   return false;
 }
 
-bool ASTContext::hasSimilarType(QualType T1, QualType T2) {
+bool ASTContext::hasSimilarType(QualType T1, QualType T2) const {
   while (true) {
     Qualifiers Quals;
     T1 = getUnqualifiedArrayType(T1, Quals);