Allows turning on checked mode on a per-isolate basis

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
===================================================================
--- runtime/vm/flow_graph_builder.cc	(revision 43472)
+++ runtime/vm/flow_graph_builder.cc	(working copy)
@@ -889,7 +889,8 @@
 
 
 void TestGraphVisitor::ReturnValue(Value* value) {
-  if (FLAG_enable_type_checks || FLAG_enable_asserts) {
+  if (Isolate::Current()->TypeChecksEnabled() ||
+      Isolate::Current()->AssertsEnabled()) {
     value = Bind(new(I) AssertBooleanInstr(condition_token_pos(), value));
   }
   Value* constant_true = Bind(new(I) ConstantInstr(Bool::True()));
@@ -924,7 +925,7 @@
         false));  // No number check.
   } else {
     branch = new(I) BranchInstr(comp);
-    branch->set_is_checked(FLAG_enable_type_checks);
+    branch->set_is_checked(Isolate::Current()->TypeChecksEnabled());
   }
   AddInstruction(branch);
   CloseFragment();
@@ -934,7 +935,7 @@
 
 
 void TestGraphVisitor::MergeBranchWithNegate(BooleanNegateInstr* neg) {
-  ASSERT(!FLAG_enable_type_checks);
+  ASSERT(!Isolate::Current()->TypeChecksEnabled());
   Value* constant_true = Bind(new(I) ConstantInstr(Bool::True()));
   StrictCompareInstr* comp =
       new(I) StrictCompareInstr(condition_token_pos(),
@@ -956,7 +957,7 @@
     MergeBranchWithComparison(comp);
     return;
   }
-  if (!FLAG_enable_type_checks) {
+  if (!Isolate::Current()->TypeChecksEnabled()) {
     BooleanNegateInstr* neg = definition->AsBooleanNegate();
     if (neg != NULL) {
       MergeBranchWithNegate(neg);
@@ -1045,7 +1046,7 @@
                                               RawPcDescriptors::kRuntimeCall));
   }
 
-  if (FLAG_enable_type_checks) {
+  if (Isolate::Current()->TypeChecksEnabled()) {
     const bool is_implicit_dynamic_getter =
         (!function.is_static() &&
         ((function.kind() == RawFunction::kImplicitGetter) ||
@@ -1244,7 +1245,8 @@
     TestGraphVisitor for_left(owner(), node->left()->token_pos());
     node->left()->Visit(&for_left);
     EffectGraphVisitor empty(owner());
-    if (FLAG_enable_type_checks || FLAG_enable_asserts) {
+    if (Isolate::Current()->TypeChecksEnabled() ||
+        Isolate::Current()->AssertsEnabled()) {
       ValueGraphVisitor for_right(owner());
       node->right()->Visit(&for_right);
       Value* right_value = for_right.value();
@@ -1309,7 +1311,8 @@
     ValueGraphVisitor for_right(owner());
     node->right()->Visit(&for_right);
     Value* right_value = for_right.value();
-    if (FLAG_enable_type_checks|| FLAG_enable_asserts) {
+    if (Isolate::Current()->TypeChecksEnabled() ||
+        Isolate::Current()->AssertsEnabled()) {
       right_value =
           for_right.Bind(new(I) AssertBooleanInstr(node->right()->token_pos(),
                                                    right_value));
@@ -1782,7 +1785,8 @@
         2,
         owner()->ic_data_array());
     if (node->kind() == Token::kNE) {
-      if (FLAG_enable_type_checks || FLAG_enable_asserts) {
+      if (Isolate::Current()->TypeChecksEnabled() ||
+          Isolate::Current()->AssertsEnabled()) {
         Value* value = Bind(result);
         result = new(I) AssertBooleanInstr(node->token_pos(), value);
       }
@@ -1828,7 +1832,8 @@
     node->operand()->Visit(&for_value);
     Append(for_value);
     Value* value = for_value.value();
-    if (FLAG_enable_type_checks || FLAG_enable_asserts) {
+    if (Isolate::Current()->TypeChecksEnabled() ||
+        Isolate::Current()->AssertsEnabled()) {
       value =
           Bind(new(I) AssertBooleanInstr(node->operand()->token_pos(), value));
     }
@@ -3431,7 +3436,7 @@
   node->value()->Visit(&for_value);
   Append(for_value);
   Value* store_value = for_value.value();
-  if (FLAG_enable_type_checks) {
+  if (Isolate::Current()->TypeChecksEnabled()) {
     store_value = BuildAssignableValue(node->value()->token_pos(),
                                        store_value,
                                        node->local().type(),
@@ -3472,7 +3477,7 @@
   node->value()->Visit(&for_value);
   Append(for_value);
   Value* store_value = for_value.value();
-  if (FLAG_enable_type_checks) {
+  if (Isolate::Current()->TypeChecksEnabled()) {
     const AbstractType& type =
         AbstractType::ZoneHandle(I, node->field().type());
     const String& dst_name = String::ZoneHandle(I, node->field().name());
@@ -3834,7 +3839,7 @@
     }
   }
 
-  if (FLAG_enable_type_checks && is_top_level_sequence) {
+  if (Isolate::Current()->TypeChecksEnabled() && is_top_level_sequence) {
     const Function& function = owner()->function();
     const int num_params = function.NumParameters();
     int pos = 0;