Add EmitGoto in x64 lithium codegen

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc	(revision 6315)
+++ src/x64/lithium-codegen-x64.cc	(working copy)
@@ -565,7 +565,19 @@
 
 
 void LCodeGen::EmitGoto(int block, LDeferredCode* deferred_stack_check) {
-  Abort("Unimplemented: %s", "EmitGoto");
+  block = chunk_->LookupDestination(block);
+  int next_block = GetNextEmittedBlock(current_block_);
+  if (block != next_block) {
+    // Perform stack overflow check if this goto needs it before jumping.
+    if (deferred_stack_check != NULL) {
+      __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
+      __ j(above_equal, chunk_->GetAssemblyLabel(block));
+      __ jmp(deferred_stack_check->entry());
+      deferred_stack_check->SetExit(chunk_->GetAssemblyLabel(block));
+    } else {
+      __ jmp(chunk_->GetAssemblyLabel(block));
+    }
+  }
 }
 
 
@@ -1155,7 +1167,6 @@
 void LCodeGen::DoStackCheck(LStackCheck* instr) {
   // Perform stack overflow check.
   NearLabel done;
-  ExternalReference stack_limit = ExternalReference::address_of_stack_limit();
   __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
   __ j(above_equal, &done);