Fix for issue 14790 - Crash when using dartium devtools

runtime/vm/stack_frame_arm.h

Index: runtime/vm/stack_frame_arm.h
===================================================================
--- runtime/vm/stack_frame_arm.h	(revision 29988)
+++ runtime/vm/stack_frame_arm.h	(working copy)
@@ -16,19 +16,24 @@
                | saved LR           |    (PC of current frame)
                | callee's PC marker |
                +--------------------+
-Current frame  | ...                | <- SP of current frame
-               | first local        |
-               | caller's PP        |
+Current frame  |*...                | <- SP of current frame
+               |*first local        |
+               |*caller's PP        |
                | caller's FP        | <- FP of current frame
                | caller's LR        |    (PC of caller frame)
                | PC marker          |    (current frame's code entry + offset)
                +--------------------+
 Caller frame   | last parameter     | <- SP of caller frame
                |  ...               |
+
+               * against a slot indicates it needs to be traversed during GC.

[regis, 2013/11/07 19:53:11]

For clarity, I would place * in all frames, not just the current one, because
this drawing of the current frame does not explicitly show the callee's
arguments, and incoming parameters are in the caller's frame.

Also, when I first saw *, I thought "pointer dereference".
How about a T (for "traversed") on the right edge where you have more space.
People are use to see the tax marker on receipts :-) 
                | first local       T|

[siva, 2013/11/07 23:08:19]

I am interested in what needs to be traversed in a frame and that is why I
limited it to just the current frame. The current frame is responsible for only
what is in it's frame. 
Done.

 */
 
 static const int kDartFrameFixedSize = 4;  // PP, FP, LR, PC marker.
 static const int kSavedPcSlotFromSp = -2;
+
+static const int kFirstObjectSlotFromFp = -2;  // Used by GC to traverse stack.
+
 static const int kFirstLocalSlotFromFp = -2;
 static const int kSavedCallerPpSlotFromFp = -1;
 static const int kSavedCallerFpSlotFromFp = 0;
@@ -44,4 +49,3 @@
 }  // namespace dart
 
 #endif  // VM_STACK_FRAME_ARM_H_
-