AST: Const-ify some methods on ClassDecl

Author: slavapestov

include/swift/AST/Decl.h

@@ -4026,7 +4026,7 @@ class ClassDecl final : public NominalTypeDecl {
   ClassDecl *getSuperclassDecl() const;
 
   /// Check if this class is a superclass or equal to the given class.
-  bool isSuperclassOf(ClassDecl *other) const;
+  bool isSuperclassOf(const ClassDecl *other) const;
 
   /// Set the superclass of this class.
   void setSuperclass(Type superclass);
@@ -4121,7 +4121,7 @@ class ClassDecl final : public NominalTypeDecl {
 
   /// Whether the class uses the ObjC object model (reference counting,
   /// allocation, etc.), the Swift model, or has no reference counting at all.
-  ReferenceCounting getObjectModel() {
+  ReferenceCounting getObjectModel() const {
     if (isForeignReferenceType())
       return ReferenceCounting::None;
 
@@ -4131,7 +4131,7 @@ class ClassDecl final : public NominalTypeDecl {
     return ReferenceCounting::Native;
   }
 
-  LayoutConstraintKind getLayoutConstraintKind() {
+  LayoutConstraintKind getLayoutConstraintKind() const {
     if (getObjectModel() == ReferenceCounting::ObjC)
       return LayoutConstraintKind::Class;
 
@@ -4261,7 +4261,7 @@ class ClassDecl final : public NominalTypeDecl {
   /// Used to determine if this class decl is a foriegn reference type. I.e., a
   /// non-reference-counted swift reference type that was imported from a C++
   /// record.
-  bool isForeignReferenceType();
+  bool isForeignReferenceType() const;
 };
 
 /// The set of known protocols for which derived conformances are supported.

lib/AST/Decl.cpp

@@ -4937,7 +4937,7 @@ void swift::simple_display(llvm::raw_ostream &out, AncestryFlags value) {
   out << " }";
 }
 
-bool ClassDecl::isSuperclassOf(ClassDecl *other) const {
+bool ClassDecl::isSuperclassOf(const ClassDecl *other) const {
   llvm::SmallPtrSet<const ClassDecl *, 8> visited;
 
   do {
@@ -5082,7 +5082,7 @@ bool ClassDecl::walkSuperclasses(
   return false;
 }
 
-bool ClassDecl::isForeignReferenceType() {
+bool ClassDecl::isForeignReferenceType() const {
   return getClangDecl() && isa<clang::RecordDecl>(getClangDecl());
 }