Handle casts from Number to FutureOr<double>.

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart

Index: pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
diff --git a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
index 20001cef3e56793e142b78209742336743dc07ec..c32826e4a6eff631fc14ce0e46b53d7cdb3cac91 100644
--- a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
+++ b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
@@ -496,7 +496,11 @@ bool strongInstanceOf(obj, type, ignoreFromWhiteList) => JS(
   let actual = $getReifiedType($obj);
   let result = $isSubtype(actual, $type);
   if (result || actual == $jsobject ||
-      actual == $int && type == $double) return true;
+      actual == $int && type == $double ||
+      (actual == $int && $_isFutureOr(type)

[vsm, 2017/03/23 19:37:44]

Can type be FutureOr<FutureOr<T>> ?

Would something like

actual == $int && $isSubtype(double, $type)

make sense?

[Leaf, 2017/03/23 20:27:31]

Good idea, done.

+       && $getGenericArgs(type)[0] == $double)) {
+    return true;
+  }
   if (result === false) return false;
   if (!$_ignoreWhitelistedErrors || ($ignoreFromWhiteList == void 0)) return result;
   if ($_ignoreTypeFailure(actual, $type)) return true;