Check that array length stays a safe integer in Array.prototype.push

src/messages.h

Index: src/messages.h
diff --git a/src/messages.h b/src/messages.h
index c97204bbab329623edd37e1a497546a56eea6646..83413e8be71590dfa3622bb9cc36c9172411cd60 100644
--- a/src/messages.h
+++ b/src/messages.h
@@ -326,6 +326,9 @@ class CallSite {
   T(NoCatchOrFinally, "Missing catch or finally after try")                    \
   T(NotIsvar, "builtin %%IS_VAR: not a variable")                              \
   T(ParamAfterRest, "Rest parameter must be last formal parameter")            \
+  T(PushPastSafeLength,                                                        \
+    "Pushing % elements on an array-like of length % "                         \
+    "is disallowed, as the total surpasses 2**53-1")                           \
   T(BadSetterRestParameter,                                                    \
     "Setter function argument must not be a rest parameter")                   \
   T(ParamDupe, "Duplicate parameter name not allowed in this context")         \