[runtime] TailCallRuntime and CallRuntime should use default argument counts

src/arm64/macro-assembler-arm64.cc

Index: src/arm64/macro-assembler-arm64.cc
diff --git a/src/arm64/macro-assembler-arm64.cc b/src/arm64/macro-assembler-arm64.cc
index abbaa32c082c59fa5457b16837d5f42445679437..054b99d0066f3a78231845bba7e5c326b30aca88 100644
--- a/src/arm64/macro-assembler-arm64.cc
+++ b/src/arm64/macro-assembler-arm64.cc
@@ -1727,20 +1727,17 @@ void MacroAssembler::InvokeBuiltin(int native_context_index, InvokeFlag flag,
 }
 
 
-void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
-                                               int num_arguments) {
-  // TODO(1236192): Most runtime routines don't need the number of
-  // arguments passed in because it is constant. At some point we
-  // should remove this need and make the runtime routine entry code
-  // smarter.
-  Mov(x0, num_arguments);
-  JumpToExternalReference(ext);
-}
-
-
-void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
-                                     int num_arguments) {
-  TailCallExternalReference(ExternalReference(fid, isolate()), num_arguments);
+void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
+  const Runtime::Function* function = Runtime::FunctionForId(fid);
+  DCHECK_EQ(1, function->result_size);
+  if (function->nargs >= 0) {
+    // TODO(1236192): Most runtime routines don't need the number of
+    // arguments passed in because it is constant. At some point we
+    // should remove this need and make the runtime routine entry code
+    // smarter.
+    Mov(x0, function->nargs);
+  }
+  JumpToExternalReference(ExternalReference(fid, isolate()));
 }