ARM64: Add comment to mterp int-to-long.

Test: Build for Nexus 9.
Change-Id: I649e71fc1cdc2a4a103159bf72ceeb005231e66f
diff --git a/runtime/interpreter/mterp/arm64/op_int_to_long.S b/runtime/interpreter/mterp/arm64/op_int_to_long.S
index 84dfb4d..45e3112 100644
--- a/runtime/interpreter/mterp/arm64/op_int_to_long.S
+++ b/runtime/interpreter/mterp/arm64/op_int_to_long.S
@@ -1,3 +1,4 @@
+    /* int-to-long vA, vB */
     lsr     w3, wINST, #12              // w3<- B
     ubfx    w4, wINST, #8, #4           // w4<- A
     GET_VREG_S x0, w3                   // x0<- sign_extend(fp[B])
diff --git a/runtime/interpreter/mterp/out/mterp_arm64.S b/runtime/interpreter/mterp/out/mterp_arm64.S
index 67f1c6e..de37e07 100644
--- a/runtime/interpreter/mterp/out/mterp_arm64.S
+++ b/runtime/interpreter/mterp/out/mterp_arm64.S
@@ -3342,6 +3342,7 @@
     .balign 128
 .L_op_int_to_long: /* 0x81 */
 /* File: arm64/op_int_to_long.S */
+    /* int-to-long vA, vB */
     lsr     w3, wINST, #12              // w3<- B
     ubfx    w4, wINST, #8, #4           // w4<- A
     GET_VREG_S x0, w3                   // x0<- sign_extend(fp[B])