Fix http://dartbug.com/23578:

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index a4c8d4153c11f06172889a1a6fecd1ac62c7ba01..06300e6b45ae1f0311905fb496532607b0c7abd8 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -23,7 +23,6 @@
 namespace dart {
 
 DECLARE_FLAG(bool, emit_edge_counters);
-DECLARE_FLAG(bool, enable_asserts);
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, use_osr);
 DECLARE_FLAG(bool, throw_on_javascript_int_overflow);
@@ -249,13 +248,13 @@ static void EmitAssertBoolean(Register reg,
   ASSERT(locs->always_calls());
   Label done;
 
-  if (Isolate::Current()->TypeChecksEnabled()) {
+  if (Isolate::Current()->flags().type_checks()) {
     __ CompareObject(reg, Bool::True());
     __ j(EQUAL, &done, Assembler::kNearJump);
     __ CompareObject(reg, Bool::False());
     __ j(EQUAL, &done, Assembler::kNearJump);
   } else {
-    ASSERT(FLAG_enable_asserts);
+    ASSERT(Isolate::Current()->flags().asserts());
     __ CompareObject(reg, Object::null_instance());
     __ j(NOT_EQUAL, &done, Assembler::kNearJump);
   }