Expunge unnecessary commentary from singular_message.cc and message.cc codegen

PiperOrigin-RevId: 597027922

src/google/protobuf/compiler/rust/accessors/singular_message.cc

@@ -36,11 +36,11 @@ void SingularMessage::InMsgImpl(Context& ctx,
                 if (ctx.is_upb()) {
                   ctx.Emit({}, R"rs(
               let submsg = unsafe { $getter_thunk$(self.inner.msg) };
-              // For upb, getters return null if the field is unset, so we need
-              // to check for null and return the default instance manually.
-              // Note that a nullptr received from upb manifests as Option::None
+              //~ For upb, getters return null if the field is unset, so we need
+              //~ to check for null and return the default instance manually.
+              //~ Note that a nullptr received from upb manifests as Option::None
               match submsg {
-                // TODO:(b/304357029)
+                //~ TODO:(b/304357029)
                 None => $prefix$View::new($pbi$::Private,
                         $pbr$::ScratchSpace::zeroed_block($pbi$::Private)),
                 Some(field) => $prefix$View::new($pbi$::Private, field),
@@ -48,8 +48,8 @@ void SingularMessage::InMsgImpl(Context& ctx,
         )rs");
                 } else {
                   ctx.Emit({}, R"rs(
-              // For C++ kernel, getters automatically return the
-              // default_instance if the field is unset.
+              //~ For C++ kernel, getters automatically return the
+              //~ default_instance if the field is unset.
               let submsg = unsafe { $getter_thunk$(self.inner.msg) };
               $prefix$View::new($pbi$::Private, submsg)
         )rs");

src/google/protobuf/compiler/rust/message.cc

@@ -110,8 +110,8 @@ void MessageDeserialize(Context& ctx, const Descriptor& msg) {
         match msg {
           None => Err($pb$::ParseError),
           Some(msg) => {
-            // This assignment causes self.arena to be dropped and to deallocate
-            // any previous message pointed/owned to by self.inner.msg.
+            //~ This assignment causes self.arena to be dropped and to deallocate
+            //~ any previous message pointed/owned to by self.inner.msg.
             self.inner.arena = arena;
             self.inner.msg = msg;
             Ok(())
@@ -437,7 +437,7 @@ void GenerateRs(Context& ctx, const Descriptor& msg) {
             {"settable_impl", [&] { MessageSettableValue(ctx, msg); }}},
            R"rs(
         #[allow(non_camel_case_types)]
-        // TODO: Implement support for debug redaction
+        //~ TODO: Implement support for debug redaction
         #[derive(Debug)]
         pub struct $Msg$ {
           inner: $pbr$::MessageInner