Revert "Better messages for optimized index errors."

sdk/lib/_internal/compiler/js_lib/js_helper.dart

Index: sdk/lib/_internal/compiler/js_lib/js_helper.dart
diff --git a/sdk/lib/_internal/compiler/js_lib/js_helper.dart b/sdk/lib/_internal/compiler/js_lib/js_helper.dart
index 7c881729b7e11d0c7e1cc41cb6b937d12c4e0f0e..1c6183d4f32f67fa48e559fe73df982f09ffb73f 100644
--- a/sdk/lib/_internal/compiler/js_lib/js_helper.dart
+++ b/sdk/lib/_internal/compiler/js_lib/js_helper.dart
@@ -1388,41 +1388,23 @@ class JsCache {
  * for example, if a non-integer index is given to an optimized
  * indexed access.
  */
-@NoInline()
 iae(argument) {
   throw _argumentError(argument);
 }
 
 /**
- * Called by generated code to throw an index-out-of-range exception, for
- * example, if a bounds check fails in an optimized indexed access.  This may
- * also be called when the index is not an integer, in which case it throws an
- * illegal-argument exception instead, like [iae], or when the receiver is null.
+ * Called by generated code to throw an index-out-of-range exception,
+ * for example, if a bounds check fails in an optimized indexed
+ * access.  This may also be called when the index is not an integer, in
+ * which case it throws an illegal-argument exception instead, like
+ * [iae], or when the receiver is null.
  */
-@NoInline()
 ioore(receiver, index) {
   if (receiver == null) receiver.length; // Force a NoSuchMethodError.
-  throw diagnoseIndexError(receiver, index);
-}
-
-/**
- * Diagnoses an indexing error. Returns the ArgumentError or RangeError that
- * describes the problem.
- */
-@NoInline()
-Error diagnoseIndexError(indexable, index) {
-  if (index is !int) return new ArgumentError.value(index, 'index');
-  int length = indexable.length;
-  // The following returns the same error that would be thrown by calling
-  // [RangeError.checkValidIndex] with no optional parameters provided.
-  if (index < 0 || index >= length) {
-    return new RangeError.index(index, indexable, 'index', null, length);
-  }
-  // The above should always match, but if it does not, use the following.
-  return new RangeError.value(index, 'index');
+  if (index is !int) iae(index);
+  throw new RangeError.value(index);
 }
 
-
 stringLastIndexOfUnchecked(receiver, element, start)
   => JS('int', r'#.lastIndexOf(#, #)', receiver, element, start);
 
@@ -2033,14 +2015,10 @@ unwrapException(ex) {
       return new StackOverflowError();
     }
 
-    // In general, a RangeError is thrown when trying to pass a number as an
-    // argument to a function that does not allow a range that includes that
-    // number. Translate to a Dart RangeError with the same message.
-    String message = tryStringifyException(ex);
-    if (message is String) {
-      message = JS('String', r'#.replace(/^RangeError:\s*/, "")', message);
-    }
-    return saveStackTrace(new RangeError(message));
+    // In general, a RangeError is thrown when trying to pass a number
+    // as an argument to a function that does not allow a range that
+    // includes that number.
+    return saveStackTrace(new ArgumentError());
   }
 
   // Check for the Firefox specific stack overflow signal.
@@ -2058,20 +2036,6 @@ unwrapException(ex) {
   return ex;
 }
 
-String tryStringifyException(ex) {
-  // Since this function is called from [unwrapException] which is called from
-  // code injected into a catch-clause, use JavaScript try-catch to avoid a
-  // potential loop if stringifying crashes.
-  return JS('String', r'''
-    (function(ex) {
-      try {
-        return String(ex);
-      } catch (e) {}
-      return null;
-    })(#)
-    ''', ex);
-}
-
 /**
  * Called by generated code to fetch the stack trace from an
  * exception. Should never return null.