Revert r31326.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
===================================================================
--- runtime/vm/intermediate_language_arm.cc	(revision 31331)
+++ runtime/vm/intermediate_language_arm.cc	(working copy)
@@ -1306,6 +1306,8 @@
 
   Label* fail = (deopt != NULL) ? deopt : &fail_label;
 
+  const bool ok_is_fall_through = (deopt != NULL);
+
   if (!compiler->is_optimizing() || (field_cid == kIllegalCid)) {
     if (!compiler->is_optimizing() && (field_reg == kNoRegister)) {
       // Currently we can't have different location summaries for optimized
@@ -1490,10 +1492,12 @@
         }
       }
     }
+    if (!ok_is_fall_through) {
+      __ b(&ok);
+    }
 
     if (deopt == NULL) {
       ASSERT(!compiler->is_optimizing());
-      __ b(&ok);
       __ Bind(fail);
 
       __ ldr(IP, FieldAddress(field_reg, Field::guarded_cid_offset()));
@@ -1508,6 +1512,7 @@
   } else {
     ASSERT(compiler->is_optimizing());
     ASSERT(deopt != NULL);
+    ASSERT(ok_is_fall_through);
     // Field guard class has been initialized and is known.
     if (field_reg != kNoRegister) {
       __ LoadObject(field_reg, Field::ZoneHandle(field().raw()));