Add an assertion to ensure that the return type and types of parameters are canonical or a TypeParam

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 05093ead27a22f6dcc501ef5b0ff15c373a0355c..0698c4e308f4ac40049e22065fb810181d261305 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -344,6 +344,12 @@ RawError* Compiler::CompileClass(const Class& cls) {
       ClassFinalizer::FinalizeClass(parse_class);
       parse_class.reset_is_marked_for_parsing();
     }
+    for (intptr_t i = (patch_list.Length() - 1); i >=0 ; i--) {
+      parse_class ^= patch_list.At(i);
+      ASSERT(!parse_class.IsNull());
+      ClassFinalizer::FinalizeClass(parse_class);
+      parse_class.reset_is_marked_for_parsing();
+    }
 
     return Error::null();
   } else {