[clang][Interp][NFC] Make Record field pointers const

Author: tbaederr

clang/lib/AST/Interp/Record.h

@@ -80,7 +80,6 @@ class Record final {
 
   unsigned getNumFields() const { return Fields.size(); }
   const Field *getField(unsigned I) const { return &Fields[I]; }
-  Field *getField(unsigned I) { return &Fields[I]; }
 
   using const_base_iter = BaseList::const_iterator;
   llvm::iterator_range<const_base_iter> bases() const {
@@ -122,7 +121,7 @@ class Record final {
   /// Mapping from declarations to bases.
   llvm::DenseMap<const RecordDecl *, Base *> BaseMap;
   /// Mapping from field identifiers to descriptors.
-  llvm::DenseMap<const FieldDecl *, Field *> FieldMap;
+  llvm::DenseMap<const FieldDecl *, const Field *> FieldMap;
   /// Mapping from declarations to virtual bases.
   llvm::DenseMap<const RecordDecl *, Base *> VirtualBaseMap;
   /// Size of the structure.