Fix wrong assert in overflow check

test/libsolidity/syntaxTests/array/length/not_too_large.sol

@@ -0,0 +1,10 @@
+// Used to cause ICE because of a too strict assert
+pragma experimental ABIEncoderV2;
+contract C {
+    struct S { uint a; T[222222222222222222222222222] sub; }
+    struct T { uint[] x; }
+    function f() public returns (uint, S memory) {
+    }
+}
+// ----
+// Warning: (52-85): Experimental features are turned on. Do not use experimental features on live deployments.