Revert "VM: New calling convention for generated code."

runtime/vm/stack_frame_arm64.h

Index: runtime/vm/stack_frame_arm64.h
diff --git a/runtime/vm/stack_frame_arm64.h b/runtime/vm/stack_frame_arm64.h
index 6a5a1dabaccb716fd7ad3f94b58070e520640c40..f2528971a227e044eb4a634e21a03c02757c36cf 100644
--- a/runtime/vm/stack_frame_arm64.h
+++ b/runtime/vm/stack_frame_arm64.h
@@ -11,14 +11,14 @@ namespace dart {
                |                    | <- TOS
 Callee frame   | ...                |
                | saved PP           |
-               | code object        |
+               | callee's PC marker |
                | saved FP           |    (FP of current frame)
                | saved PC           |    (PC of current frame)
                +--------------------+
 Current frame  | ...               T| <- SP of current frame
                | first local       T|
                | caller's PP       T|
-               | code object       T|    (current frame's code object)
+               | PC marker          |    (current frame's code entry + offset)
                | caller's FP        | <- FP of current frame
                | caller's LR        |    (PC of caller frame)
                +--------------------+
@@ -31,7 +31,7 @@ Caller frame   | last parameter     | <- SP of caller frame
 static const int kDartFrameFixedSize = 4;  // PP, FP, LR, PC marker.
 static const int kSavedPcSlotFromSp = -1;
 
-static const int kFirstObjectSlotFromFp = -1;  // Used by GC to traverse stack.
+static const int kFirstObjectSlotFromFp = -2;  // Used by GC to traverse stack.
 
 static const int kFirstLocalSlotFromFp = -3;
 static const int kSavedCallerPpSlotFromFp = -2;