target/arm: Avoid tcg_const_ptr in handle_vec_simd_sqshrn

It is easy enough to use mov instead of or-with-zero
and relying on the optimizer to fold away the or.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 2ad7c48..082a8b8 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -8459,7 +8459,7 @@
     tcg_rn = tcg_temp_new_i64();
     tcg_rd = tcg_temp_new_i64();
     tcg_rd_narrowed = tcg_temp_new_i32();
-    tcg_final = tcg_const_i64(0);
+    tcg_final = tcg_temp_new_i64();
 
     if (round) {
         tcg_round = tcg_constant_i64(1ULL << (shift - 1));
@@ -8473,7 +8473,11 @@
                                 false, is_u_shift, size+1, shift);
         narrowfn(tcg_rd_narrowed, cpu_env, tcg_rd);
         tcg_gen_extu_i32_i64(tcg_rd, tcg_rd_narrowed);
-        tcg_gen_deposit_i64(tcg_final, tcg_final, tcg_rd, esize * i, esize);
+        if (i == 0) {
+            tcg_gen_mov_i64(tcg_final, tcg_rd);
+        } else {
+            tcg_gen_deposit_i64(tcg_final, tcg_final, tcg_rd, esize * i, esize);
+        }
     }
 
     if (!is_q) {