Oilpan: Query stack frame register instead of manual bookkeeping

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index 83e9e5a94975dffd0c226c3c36f5b67f034e96b0..c8b4de824c2cccabe6be6aa4cdd74852acae200a 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -2326,6 +2326,8 @@ void Heap::collectGarbage(ThreadState::StackState stackState, ThreadState::GCTyp
     ThreadState::NoAllocationScope noAllocationScope(state);
 
     preGC();
+    s_markingVisitor->configureEagerTraceLimit();
+    ASSERT(s_markingVisitor->canTraceEagerly());
 
     Heap::resetMarkedObjectSize();
     Heap::resetAllocatedObjectSize();
@@ -2381,6 +2383,8 @@ void Heap::collectGarbageForTerminatingThread(ThreadState* state)
         ThreadState::NoAllocationScope noAllocationScope(state);
 
         state->preGC();
+        s_markingVisitor->configureEagerTraceLimit();
+        ASSERT(s_markingVisitor->canTraceEagerly());
 
         // 1. Trace the thread local persistent roots. For thread local GCs we
         // don't trace the stack (ie. no conservative scanning) since this is