Reapply "Do not directly load smi constants larger than a 16 bit..."

runtime/vm/assembler_arm.h

Index: runtime/vm/assembler_arm.h
diff --git a/runtime/vm/assembler_arm.h b/runtime/vm/assembler_arm.h
index bd8059614ff864fe78c700793177192f3ef9a206..0ba7df7d318acd926167275b6e3631ce89893d54 100644
--- a/runtime/vm/assembler_arm.h
+++ b/runtime/vm/assembler_arm.h
@@ -12,6 +12,7 @@
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/constants_arm.h"
+#include "vm/object.h"
 #include "vm/simulator.h"
 
 namespace dart {
@@ -733,6 +734,11 @@ class Assembler : public ValueObject {
   // Emit data (e.g encoded instruction or immediate) in instruction stream.
   void Emit(int32_t value);
 
+  // On some other platforms, we draw a distinction between safe and unsafe
+  // smis.
+  static bool IsSafe(const Object& object) { return true; }
+  static bool IsSafeSmi(const Object& object) { return object.IsSmi(); }
+
  private:
   AssemblerBuffer buffer_;  // Contains position independent code.
   GrowableObjectArray& object_pool_;  // Objects and patchable jump targets.