Allow the native resolver to setup whether it needs the Dart API scope to

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
===================================================================
--- runtime/vm/stub_code_arm.cc	(revision 31283)
+++ runtime/vm/stub_code_arm.cc	(working copy)
@@ -181,8 +181,14 @@
   // For now, space is reserved on the stack and we pass a pointer to it.
   __ stm(IA, SP,  (1 << R0) | (1 << R1) | (1 << R2) | (1 << R3));
   __ mov(R0, ShifterOperand(SP));  // Pass the pointer to the NativeArguments.
+
+  // Call native function (setsup scope if not leaf function).
+  Label leaf_call;
+  Label done;
+  __ TestImmediate(R1, NativeArguments::AutoSetupScopeMask());
+  __ b(&leaf_call, EQ);
+
   __ mov(R1, ShifterOperand(R5));  // Pass the function entrypoint to call.
-
   // Call native function invocation wrapper or redirection via simulator.
 #if defined(USING_SIMULATOR)
   uword entry = reinterpret_cast<uword>(NativeEntry::NativeCallWrapper);
@@ -193,7 +199,14 @@
 #else
   __ BranchLink(&NativeEntry::NativeCallWrapperLabel());
 #endif
+  __ b(&done);
 
+  __ Bind(&leaf_call);
+  // Call native function or redirection via simulator.
+  __ blx(R5);
+
+  __ Bind(&done);
+
   // Reset exit frame information in Isolate structure.
   __ LoadImmediate(R2, 0);
   __ StoreToOffset(kWord, R2, CTX, Isolate::top_exit_frame_info_offset());