[dart2wasm] Simplify type test function names

Instead of

    <obj> is Class(JSUint16ArrayImpl)

generate

    <obj> is JSUint16ArrayImpl

in type test functions.

Change-Id: I98e294291f91d3a117052e42b774a907c95ad6b4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/374001
Reviewed-by: Martin Kustermann <[email protected]>
Commit-Queue: Ömer Ağacan <[email protected]>

Author: osa1

pkg/dart2wasm/lib/types.dart

@@ -559,7 +559,7 @@ class Types {
             [argumentType],
             [w.NumType.i32],
           ),
-          '<obj> is ${testedAgainstType.classNode}');
+          '<obj> is ${testedAgainstType.classNode.name}');
 
       final b = function.body;
       b.local_get(b.locals[0]);
@@ -623,7 +623,7 @@ class Types {
             [argumentType],
             [returnType],
           ),
-          '<obj> as ${testedAgainstType.classNode}');
+          '<obj> as ${testedAgainstType.classNode.name}');
 
       final b = function.body;
       w.Label asCheckBlock = b.block();