Add javascript compatibility warnings for integer values and integral double

tests/standalone/javascript_compatibility_errors_test.dart

Index: tests/standalone/javascript_compatibility_errors_test.dart
===================================================================
--- tests/standalone/javascript_compatibility_errors_test.dart	(revision 37016)
+++ tests/standalone/javascript_compatibility_errors_test.dart	(working copy)
@@ -7,7 +7,7 @@
 import "package:expect/expect.dart";
 
 f(x, y) {
-  // Unoptimized code.
+  // Unoptimized and optimized code.
   1 is double;  /// 00: compile-time error
   if (1 is double) { x++; }  /// 01: compile-time error
   try { 1 as double; } on CastError catch (e) { }  /// 02: compile-time error
@@ -40,35 +40,41 @@
   b = b.substring(1);
   if (identical(a, b)) { }  /// 28: ok
 
+  if (identical(x, y)) { }  /// 29: ok
+  if (identical(y, x)) { }  /// 30: ok
+
   if (x > 10) {
     // Optimized code.
-    x is double;  /// 30: ok
-    if (x is double) { }  /// 31: ok
-    try { x as double; } on CastError catch (e) { }  /// 32: ok
-    try { var z = x as double; } on CastError catch (e) { }  /// 33: ok
-    y is int;  /// 34: ok
-    if (y is int) { }  /// 35: ok
-    try { y as int; } on CastError catch (e) { }  /// 36: ok
-    try { var z = y as int; } on CastError catch (e) { }  /// 37: ok
+    x is double;  /// 40: ok
+    if (x is double) { }  /// 41: ok
+    try { x as double; } on CastError catch (e) { }  /// 42: ok
+    try { var z = x as double; } on CastError catch (e) { }  /// 43: ok
+    y is int;  /// 44: ok
+    if (y is int) { }  /// 45: ok
+    try { y as int; } on CastError catch (e) { }  /// 46: ok
+    try { var z = y as int; } on CastError catch (e) { }  /// 47: ok
 
-    "${1.0}";  /// 40: compile-time error
-    var z = "${1.0}";  /// 41: compile-time error
-    (1.0).toString();  /// 42: ok
-    var z = (1.0).toString();  /// 43: ok
-    "$y";  /// 44: ok
-    var z = "$y";  /// 45: ok
-    y.toString();  /// 46: ok
-    var z = y.toString();  /// 47: ok
+    "${1.0}";  /// 50: compile-time error
+    var z = "${1.0}";  /// 51: compile-time error
+    (1.0).toString();  /// 52: ok
+    var z = (1.0).toString();  /// 53: ok
+    "$y";  /// 54: ok
+    var z = "$y";  /// 55: ok
+    y.toString();  /// 56: ok
+    var z = y.toString();  /// 57: ok
 
     var a = "yz";
     var b = "xyz";
     b = b.substring(1);
-    if (identical(a, b)) { }  /// 48: ok
+    if (identical(a, b)) { }  /// 58: ok
+
+    if (identical(x, y)) { }  /// 59: ok
+    if (identical(y, x)) { }  /// 60: ok
   }
 }
 
 k(x, y) {
-  // Unoptimized code.
+  // Unoptimized and optimized code.
   1.5 is double;
   if (1.5 is double) { x++; }
   try { 1.5 as double; } on CastError catch (e) { }
@@ -105,6 +111,14 @@
   y.toString();
   z = y.toString();
 
+  var a = "xyz";
+  var b = "xyz";
+  b = b.substring(1);
+  if (identical(a, b)) { }
+
+  if (identical(x, y)) { }
+  if (identical(y, x)) { }
+
   if (x > 10) {
     // Optimized code.
     x is double;
@@ -124,6 +138,14 @@
     z = "$y";
     y.toString();
     z = y.toString();
+
+    var a = "xyz";
+    var b = "xyz";
+    b = b.substring(1);
+    if (identical(a, b)) { }
+
+    if (identical(x, y)) { }
+    if (identical(y, x)) { }
   }
 }