Type check binary expressions

test/dart_codegen/expect/core/exceptions.dart

 part of dart.core;
  abstract class Exception {factory Exception([var message]) => new _ExceptionImplementation(message);
 }
  class _ExceptionImplementation implements Exception {final message;
  _ExceptionImplementation([this.message]);
  String toString() {
 if (message == null) return "Exception";
  return "Exception: $message";
 }
 }
  class FormatException implements Exception {final String message;
  final source;
  final int offset;
  const FormatException([this.message = "", this.source, this.offset = -1]);
  String toString() {
 String report = "FormatException";
  if (message != null && "" != message) {
 report = "$report: $message";
 }
  int offset = this.offset;
  if (source is! String) {
 if (offset != -1) {
   report += " (at offset $offset)";
   }
  return report;
 }
- if (offset != -1 && (offset < 0 || offset > source.length)) {
+ if (offset != -1 && (offset < 0 || offset > DEVC$RT.cast(source.length, dynamic, num, "DynamicCast", """line 108, column 49 of dart:core/exceptions.dart: """, source.length is num, true))) {
 offset = -1;
 }
  if (offset == -1) {
 String source = ((__x3) => DEVC$RT.cast(__x3, dynamic, String, "DynamicCast", """line 113, column 23 of dart:core/exceptions.dart: """, __x3 is String, true))(this.source);
  if (source.length > 78) {
   source = source.substring(0, 75) + "...";
   }
  return "$report\n$source";
 }
  int lineNum = 1;
@@ skipping 14 matching lines @@
    lastWasCR = true;
   }
 }
  if (lineNum > 1) {
 report += " (at line $lineNum, character ${offset - lineStart + 1})\n";
 }
  else {
 report += " (at character ${offset + 1})\n";
 }
  int lineEnd = DEVC$RT.cast(source.length, dynamic, int, "DynamicCast", """line 141, column 19 of dart:core/exceptions.dart: """, source.length is int, true);
- for (int i = offset; i < source.length; i++) {
+ for (int i = offset; i < DEVC$RT.cast(source.length, dynamic, num, "DynamicCast", """line 142, column 30 of dart:core/exceptions.dart: """, source.length is num, true); i++) {
 int char = ((__x5) => DEVC$RT.cast(__x5, dynamic, int, "DynamicCast", """line 143, column 18 of dart:core/exceptions.dart: """, __x5 is int, true))(source.codeUnitAt(i));
  if (char == 0x0a || char == 0x0d) {
   lineEnd = i;
    break;
   }
 }
  int length = lineEnd - lineStart;
  int start = lineStart;
  int end = lineEnd;
  String prefix = "";
@@ skipping 15 matching lines @@
   }
 }
  String slice = ((__x6) => DEVC$RT.cast(__x6, dynamic, String, "DynamicCast", """line 171, column 20 of dart:core/exceptions.dart: """, __x6 is String, true))(source.substring(start, end));
  int markOffset = offset - start + prefix.length;
  return "$report$prefix$slice$postfix\n${" " * markOffset}^\n";
 }
 }
  class IntegerDivisionByZeroException implements Exception {const IntegerDivisionByZeroException();
  String toString() => "IntegerDivisionByZeroException";
 }