accel/tcg: Don't use TARGET_LONG_BITS in decode_sleb128

When we changed decode_sleb128 from target_long to
int64_t, we failed to adjust the shift limit.

Cc: qemu-stable@nongnu.org
Fixes: c9ad8d27caa ("tcg: Widen gen_insn_data to uint64_t")
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
(cherry picked from commit 9401f91b9b0c46886388735b3f2033a9c254895a)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

accel/tcg/translate-all.c

@@ -106,7 +106,7 @@ static int64_t decode_sleb128(const uint8_t **pp)
         val |= (int64_t)(byte & 0x7f) << shift;
         shift += 7;
     } while (byte & 0x80);
-    if (shift < TARGET_LONG_BITS && (byte & 0x40)) {
+    if (shift < 64 && (byte & 0x40)) {
         val |= -(int64_t)1 << shift;
     }