Handle dynamic as bottom inside of function type reps

test/codegen/expect/constructors.js

Index: test/codegen/expect/constructors.js
diff --git a/test/codegen/expect/constructors.js b/test/codegen/expect/constructors.js
index 5b26e6caed729d4fc6771518251d79242c964985..c6c7cf5b4f98ae3f96df8fbfd40d7d496995af72 100644
--- a/test/codegen/expect/constructors.js
+++ b/test/codegen/expect/constructors.js
@@ -121,7 +121,7 @@ dart_library.library('constructors', null, /* Imports */[
     }
   }
   dart.setSignature(L, {
-    constructors: () => ({L: [L, [core.Object]]})
+    constructors: () => ({L: [L, [dart.dynamic]]})
   });
   class M extends L {
     named(x) {
@@ -183,7 +183,7 @@ dart_library.library('constructors', null, /* Imports */[
       }
     }
     dart.setSignature(Q, {
-      constructors: () => ({Q: [Q$(T), [core.Object]]}),
+      constructors: () => ({Q: [Q$(T), [dart.dynamic]]}),
       methods: () => ({
         bar: [core.String, []],
         bar2: [core.String, []]