tcg: Increase width of temp_subindex

We need values 0-3 for TCG_TYPE_I128 on 32-bit hosts.

Cc: qemu-stable@nongnu.org
Fixes: 43eef72 ("tcg: Add temp allocation for TCGv_i128")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2159
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>

include/tcg/tcg.h

@@ -412,7 +412,7 @@ typedef struct TCGTemp {
     unsigned int mem_coherent:1;
     unsigned int mem_allocated:1;
     unsigned int temp_allocated:1;
-    unsigned int temp_subindex:1;
+    unsigned int temp_subindex:2;
 
     int64_t val;
     struct TCGTemp *mem_base;