Support inlining at call-sites with mismatched number of arguments.

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 fee2f4f2ab98bbfd2351e821a920e3271608c5f2..1236e3870b20e84d2877ffa7a5b0cb9b51192749 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1000,14 +1000,16 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
   LEnvironment* outer =
       CreateEnvironment(hydrogen_env->outer(), argument_index_accumulator);
   int ast_id = hydrogen_env->ast_id();
-  ASSERT(ast_id != AstNode::kNoNumber);
+  ASSERT(ast_id != AstNode::kNoNumber || hydrogen_env->is_arguments_adaptor());
   int value_count = hydrogen_env->length();
   LEnvironment* result = new LEnvironment(hydrogen_env->closure(),
+                                          hydrogen_env->is_arguments_adaptor(),
                                           ast_id,
                                           hydrogen_env->parameter_count(),
                                           argument_count_,
                                           value_count,
                                           outer);
+  int argument_index = *argument_index_accumulator;
   for (int i = 0; i < value_count; ++i) {
     if (hydrogen_env->is_special_index(i)) continue;
 
@@ -1016,13 +1018,17 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
     if (value->IsArgumentsObject()) {
       op = NULL;
     } else if (value->IsPushArgument()) {
-      op = new LArgument((*argument_index_accumulator)++);
+      op = new LArgument(argument_index++);
     } else {
       op = UseAny(value);
     }
     result->AddValue(op, value->representation());
   }
 
+  if (!hydrogen_env->is_arguments_adaptor()) {
+    *argument_index_accumulator = argument_index;
+  }
+
   return result;
 }
 
@@ -2245,6 +2251,7 @@ LInstruction* LChunkBuilder::DoEnterInlined(HEnterInlined* instr) {
   HEnvironment* outer = current_block_->last_environment();
   HConstant* undefined = graph()->GetConstantUndefined();
   HEnvironment* inner = outer->CopyForInlining(instr->closure(),
+                                               instr->arguments_count(),
                                                instr->function(),
                                                undefined,
                                                instr->call_kind());
@@ -2255,7 +2262,8 @@ LInstruction* LChunkBuilder::DoEnterInlined(HEnterInlined* instr) {
 
 
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
-  HEnvironment* outer = current_block_->last_environment()->outer();
+  HEnvironment* outer = current_block_->last_environment()->
+      DiscardInlined(false);
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }