tcg/optimize: Optimize bswap

Somehow we forgot these operations, once upon a time.
This will allow immediate stores to have their bswap
optimized away.
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>

tcg/optimize.c

@@ -353,6 +353,15 @@ static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y)
     CASE_OP_32_64(ext16u):
         return (uint16_t)x;
 
+    CASE_OP_32_64(bswap16):
+        return bswap16(x);
+
+    CASE_OP_32_64(bswap32):
+        return bswap32(x);
+
+    case INDEX_op_bswap64_i64:
+        return bswap64(x);
+
     case INDEX_op_ext_i32_i64:
     case INDEX_op_ext32s_i64:
         return (int32_t)x;
@@ -1105,6 +1114,9 @@ void tcg_optimize(TCGContext *s)
         CASE_OP_32_64(ext16s):
         CASE_OP_32_64(ext16u):
         CASE_OP_32_64(ctpop):
+        CASE_OP_32_64(bswap16):
+        CASE_OP_32_64(bswap32):
+        case INDEX_op_bswap64_i64:
         case INDEX_op_ext32s_i64:
         case INDEX_op_ext32u_i64:
         case INDEX_op_ext_i32_i64: