Update int value in test to be Dart2.0 complaint, ints are now restricted to 64 bits.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=180961409
diff --git a/test/number_format_test.dart b/test/number_format_test.dart
index 91ddab2..77ddb8c 100644
--- a/test/number_format_test.dart
+++ b/test/number_format_test.dart
@@ -45,8 +45,8 @@
 
 /// Test numbers that won't work in Javascript because they're too big.
 var testNumbersOnlyForTheVM = {
-  "10,000,000,000,000,000,000,000,000,000,000":
-      10000000000000000000000000000000,
+  "9,000,000,000,000,000,000":
+      9000000000000000000,
 };
 
 get allTestNumbers => new Map.from(testNumbersWeCanReadBack)