exec-all.h: increase OPC_BUF_SIZE

Increase OPC_BUF_SIZE to compensate the MAX_OP_PER_INSTR's increase.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
diff --git a/exec-all.h b/exec-all.h
index ef783d8..93e0b5d 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -37,7 +37,7 @@
 #define MAX_OP_PER_INSTR 96
 /* A Call op needs up to 6 + 2N parameters (N = number of arguments).  */
 #define MAX_OPC_PARAM 10
-#define OPC_BUF_SIZE 512
+#define OPC_BUF_SIZE 640
 #define OPC_MAX_SIZE (OPC_BUF_SIZE - MAX_OP_PER_INSTR)
 
 /* Maximum size a TCG op can expand to.  This is complicated because a