Implement ES6 rest parameters

src/arm64/code-stubs-arm64.cc

Index: src/arm64/code-stubs-arm64.cc
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
index 9a26c3d60b720c733870031ee79f9fc1f868d1ff..ba5ed16c9a0ecf0f97018e46581dc2290c8f60ce 100644
--- a/src/arm64/code-stubs-arm64.cc
+++ b/src/arm64/code-stubs-arm64.cc
@@ -2150,6 +2150,53 @@ void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
 }
 
 
+void RestParamAccessStub::GenerateNew(MacroAssembler* masm) {
+  // Stack layout on entry.
+  //  jssp[0]:  index of rest parameter (tagged)
+  //  jssp[8]:  number of parameters (tagged)
+  //  jssp[16]: address of receiver argument
+  //
+  // Returns pointer to result object in x0.
+
+  // Get the stub arguments from the frame, and make an untagged copy of the
+  // parameter count.
+  Register rest_index_smi = x1;
+  Register param_count_smi = x2;
+  Register params = x3;
+  Register param_count = x13;
+  __ Pop(rest_index_smi, param_count_smi, params);
+  __ SmiUntag(param_count, param_count_smi);
+
+  // Test if arguments adaptor needed.
+  Register caller_fp = x11;
+  Register caller_ctx = x12;
+  Label runtime;
+  __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ldr(caller_ctx, MemOperand(caller_fp,
+                                StandardFrameConstants::kContextOffset));
+  __ Cmp(caller_ctx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ B(ne, &runtime);
+
+  //   x1   rest_index_smi    index of rest parameter
+  //   x2   param_count_smi   number of parameters passed to function (smi)
+  //   x3   params            pointer to parameters
+  //   x11  caller_fp         caller's frame pointer
+  //   x13  param_count       number of parameters passed to function
+
+  // Patch the argument length and parameters pointer.
+  __ Ldr(param_count_smi,
+         MemOperand(caller_fp,
+                    ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ SmiUntag(param_count, param_count_smi);
+  __ Add(x10, caller_fp, Operand(param_count, LSL, kPointerSizeLog2));
+  __ Add(params, x10, StandardFrameConstants::kCallerSPOffset);
+
+  __ Bind(&runtime);
+  __ Push(params, param_count_smi, rest_index_smi);
+  __ TailCallRuntime(Runtime::kNewRestParam, 3, 1);
+}
+
+
 void RegExpExecStub::Generate(MacroAssembler* masm) {
 #ifdef V8_INTERPRETED_REGEXP
   __ TailCallRuntime(Runtime::kRegExpExecRT, 4, 1);