[torque] Use "." instead of "->" on Object

{Object::operator->} will be removed soon.

R=tebbi@chromium.org

Bug: v8:9183, v8:3770
Change-Id: Ifb7754c16055aec41dd30a92e81521a830de4f26
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624210Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61750}

src/torque/implementation-visitor.cc

@@ -3393,7 +3393,7 @@ void ImplementationVisitor::GenerateClassVerifiers(
           // consistent, but for now we'll just avoid the bad case.
           cc_contents << "  " << super_name << "Verify(o, isolate);\n";
         } else {
-          cc_contents << "  o->" << super_name << "Verify(isolate);\n";
+          cc_contents << "  o." << super_name << "Verify(isolate);\n";
         }
       }