Reverting 3159, 3151 and 3150

src/ia32/frames-ia32.cc

Index: src/ia32/frames-ia32.cc
===================================================================
--- src/ia32/frames-ia32.cc	(revision 3173)
+++ src/ia32/frames-ia32.cc	(working copy)
@@ -56,14 +56,19 @@
   state->fp = fp;
   state->sp = sp;
   state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
-  return EXIT;
+  // Determine frame type.
+  if (Memory::Address_at(fp + ExitFrameConstants::kDebugMarkOffset) != 0) {
+    return EXIT_DEBUG;
+  } else {
+    return EXIT;
+  }
 }
 
 
 void ExitFrame::Iterate(ObjectVisitor* v) const {
-  v->VisitPointer(&code_slot());
-  // The arguments are traversed as part of the expression stack of
-  // the calling frame.
+  // Exit frames on IA-32 do not contain any pointers. The arguments
+  // are traversed as part of the expression stack of the calling
+  // frame.
 }