Support unaligned integer loads on ARM and MIPS.

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 4c172275f8cc9622e9e5af4d1779dcd6c7803ef8..3f07561d280df9f4c9f9929b106d461b63bb1373 100644
--- a/runtime/vm/assembler_arm.h
+++ b/runtime/vm/assembler_arm.h
@@ -971,6 +971,14 @@ class Assembler : public ValueObject {
                                     intptr_t index,
                                     Register temp);
 
+  void LoadElementAddressForIntIndex(Register address,
+                                     bool is_load,
+                                     bool is_external,
+                                     intptr_t cid,
+                                     intptr_t index_scale,
+                                     Register array,
+                                     intptr_t index);
+
   Address ElementAddressForRegIndex(bool is_load,
                                     bool is_external,
                                     intptr_t cid,
@@ -978,6 +986,20 @@ class Assembler : public ValueObject {
                                     Register array,
                                     Register index);
 
+  void LoadElementAddressForRegIndex(Register address,
+                                     bool is_load,
+                                     bool is_external,
+                                     intptr_t cid,
+                                     intptr_t index_scale,
+                                     Register array,
+                                     Register index);
+
+  void LoadHalfWordUnaligned(Register dst, Register addr, Register tmp);
+  void LoadHalfWordUnsignedUnaligned(Register dst, Register addr, Register tmp);
+  void StoreHalfWordUnaligned(Register src, Register addr, Register tmp);
+  void LoadWordUnaligned(Register dst, Register addr, Register tmp);
+  void StoreWordUnaligned(Register src, Register addr, Register tmp);
+
   // If allocation tracing for |cid| is enabled, will jump to |trace| label,
   // which will allocate in the runtime where tracing occurs.
   void MaybeTraceAllocation(intptr_t cid,