[upstreaming][NFC] Remove undefined method in ClangASTContext::RemoveFastQualifiers

Author: Teemperor

lldb/include/lldb/Symbol/ClangASTContext.h

@@ -692,8 +692,6 @@ class ClangASTContext : public TypeSystem {
   // If the current object represents a typedef type, get the underlying type
   CompilerType GetTypedefedType(lldb::opaque_compiler_type_t type) override;
 
-  static CompilerType RemoveFastQualifiers(const CompilerType &type);
-
   // Create related types using the current type's AST
   CompilerType GetBasicTypeFromAST(lldb::BasicType basic_type) override;