SSI implementation.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 574970c6994e701cab44a590ac58d0f6aa121479..7d1d82f29fe5ec1a3228376fa404d5129ac5307e 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -978,6 +978,12 @@ LInstruction* LChunkBuilder::DoWrapReceiver(HWrapReceiver* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoSsiDefinition(HSsiDefinition* instr) {
+  UNREACHABLE();
+  return NULL;
+}
+
+
 LInstruction* LChunkBuilder::DoApplyArguments(HApplyArguments* instr) {
   LOperand* function = UseFixed(instr->function(), rdi);
   LOperand* receiver = UseFixed(instr->receiver(), rax);