Fix OSR for nested loops.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 83706ad0e9bbe1682bfac9da409d92c02a3b18fb..e17a7fa932e99ee3c2c2076526097ec3db1d4180 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -349,13 +349,6 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   // the deoptimization input data found in the optimized code.
   RecordBackEdge(stmt->OsrEntryId());
 
-  // Loop stack checks can be patched to perform on-stack replacement. In
-  // order to decide whether or not to perform OSR we embed the loop depth
-  // in a test instruction after the call so we can extract it from the OSR
-  // builtin.
-  ASSERT(loop_depth() > 0);
-  __ testl(rax, Immediate(Min(loop_depth(), Code::kMaxLoopNestingMarker)));
-
   EmitProfilingCounterReset();
 
   __ bind(&ok);