Add asserts and state tracking to ensure that we do not call

src/x64/debug-x64.cc

Index: src/x64/debug-x64.cc
===================================================================
--- src/x64/debug-x64.cc	(revision 8110)
+++ src/x64/debug-x64.cc	(working copy)
@@ -100,7 +100,8 @@
                                           RegList non_object_regs,
                                           bool convert_call_to_jmp) {
   // Enter an internal frame.
-  __ EnterInternalFrame();
+{
+  FrameScope scope(masm, StackFrame::INTERNAL);
 
   // Store the registers containing live values on the expression stack to
   // make sure that these are correctly updated during GC. Non object values
@@ -157,7 +158,7 @@
   }
 
   // Get rid of the internal frame.
-  __ LeaveInternalFrame();
+}
 
   // If this call did not replace a call but patched other code then there will
   // be an unwanted return address left on the stack. Here we get rid of that.