Expose set_source service command for functions

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 915b853962f6c2e61cb6113ef2845f1d18031f62..cdf9ddb515c0212cd24dd0a2446c5f6802c7f57b 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -1107,6 +1107,7 @@ class Class : public Object {
   RawArray* functions() const { return raw_ptr()->functions_; }
   void SetFunctions(const Array& value) const;
   void AddFunction(const Function& function) const;
+  void RemoveFunction(const Function& function) const;
   intptr_t FindFunctionIndex(const Function& function) const;
   RawFunction* FunctionFromIndex(intptr_t idx) const;
   intptr_t FindImplicitClosureFunctionIndex(const Function& needle) const;
@@ -2274,6 +2275,7 @@ FOR_EACH_FUNCTION_KIND_BIT(DEFINE_BIT)
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(Function, Object);
   friend class Class;
+  friend class Parser;  // For set_eval_script.
   // RawFunction::VisitFunctionPointers accesses the private constructor of
   // Function.
   friend class RawFunction;