Fix unoptimized code calling a disabled code when --verify-on-transition is enabled.

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
diff --git a/runtime/vm/stub_code_arm.cc b/runtime/vm/stub_code_arm.cc
index d9ff9560014c6b0d925b2ac8de7978a898920fc5..b7c23465296cde75cb83c95c314380d826312f60 100644
--- a/runtime/vm/stub_code_arm.cc
+++ b/runtime/vm/stub_code_arm.cc
@@ -1896,12 +1896,12 @@ void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
   __ Push(R8);
   __ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry, 1);
   __ Pop(R0);  // Discard argument.
-  __ Pop(R0);  // Get Code object
+  __ Pop(R0);  // Get Function object
   __ Pop(R4);  // Restore argument descriptor.
   __ LeaveStubFrame();
-  __ mov(CODE_REG, Operand(R0));
-  __ ldr(R0, FieldAddress(R0, Code::entry_point_offset()));
-  __ bx(R0);
+  __ ldr(CODE_REG, FieldAddress(R0, Function::code_offset()));
+  __ ldr(R1, FieldAddress(R0, Function::entry_point_offset()));
+  __ bx(R1);
   __ bkpt(0);
 }