Fixes a couple problems with GC of unoptimized code.

runtime/vm/stack_frame.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/stack_frame.h"
 
 #include "vm/assembler.h"
 #include "vm/deopt_instructions.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 68 matching lines @@
       RawObject** last = reinterpret_cast<RawObject**>(
           fp() + (kFirstLocalSlotFromFp * kWordSize));
 
       // A stack map is present in the code object, use the stack map to
       // visit frame slots which are marked as having objects.
       //
       // The layout of the frame is (lower addresses to the right):
       // | spill slots | outgoing arguments | saved registers |
       // |XXXXXXXXXXXXX|--------------------|XXXXXXXXXXXXXXXXX|
       //
-      // The splill slots and any saved registers are described in the stack
+      // The spill slots and any saved registers are described in the stack
       // map.  The outgoing arguments are assumed to be tagged; the number
       // of outgoing arguments is not explicitly tracked.
       //
       // TODO(kmillikin): This does not handle slow path calls with
       // arguments, where the arguments are pushed after the live registers.
       // Enable such calls.
       intptr_t length = map.Length();
       // Spill slots are at the 'bottom' of the frame.
       intptr_t spill_slot_count = length - map.RegisterBitCount();
       for (intptr_t bit = 0; bit < spill_slot_count; ++bit) {
@@ skipping 328 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return index;
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart