[interpreter] Add OSR nesting level to bytecode header.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index df3010181e7f462935c2f650dbba08b3e1531699..678f830f0844d2d916b1064304e843cd50397dfb 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4096,6 +4096,15 @@ void BytecodeArray::set_interrupt_budget(int interrupt_budget) {
   WRITE_INT_FIELD(this, kInterruptBudgetOffset, interrupt_budget);
 }
 
+int BytecodeArray::osr_loop_nesting_level() const {
+  return READ_INT_FIELD(this, kOSRNestingLevelOffset);
+}
+
+void BytecodeArray::set_osr_loop_nesting_level(int depth) {
+  DCHECK(0 <= depth && depth <= Code::kMaxLoopNestingMarker);

[rmcilroy, 2016/07/22 09:46:01]

Probably not worth the churn, but maybe we could move
Code::kMaxLoopNestingMarker to AbstractCode?

[Michael Starzinger, 2016/07/25 10:24:42]

Done.

+  WRITE_INT_FIELD(this, kOSRNestingLevelOffset, depth);
+}
+
 int BytecodeArray::parameter_count() const {
   // Parameter count is stored as the size on stack of the parameters to allow
   // it to be used directly by generated code.