fixup! C model library: Support ARM64 va_list types

This extends 4d0164f to uses within `__CPROVER_OBJECT_SIZE`.

Fixes: diffblue#8357

src/ansi-c/library/stdio.c

@@ -1135,7 +1135,7 @@ int vfscanf(FILE *restrict stream, const char *restrict format, va_list arg)
 
   (void)*format;
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&arg) <
-        __CPROVER_OBJECT_SIZE(arg))
+        __CPROVER_OBJECT_SIZE(*(void **)&arg))
   {
     void *a = va_arg(arg, void *);
     __CPROVER_havoc_object(a);
@@ -1233,7 +1233,7 @@ int __stdio_common_vfscanf(
 
   (void)*format;
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&args) <
-        __CPROVER_OBJECT_SIZE(args))
+        __CPROVER_OBJECT_SIZE(*(void **)&args))
   {
     void *a = va_arg(args, void *);
     __CPROVER_havoc_object(a);
@@ -1312,7 +1312,7 @@ __CPROVER_HIDE:;
   (void)*s;
   (void)*format;
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&arg) <
-        __CPROVER_OBJECT_SIZE(arg))
+        __CPROVER_OBJECT_SIZE(*(void **)&arg))
   {
     void *a = va_arg(arg, void *);
     __CPROVER_havoc_object(a);
@@ -1388,7 +1388,7 @@ int __stdio_common_vsscanf(
   (void)*s;
   (void)*format;
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&args) <
-        __CPROVER_OBJECT_SIZE(args))
+        __CPROVER_OBJECT_SIZE(*(void **)&args))
   {
     void *a = va_arg(args, void *);
     __CPROVER_havoc_object(a);
@@ -1774,7 +1774,7 @@ int vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
   (void)*fmt;
 
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&ap) <
-        __CPROVER_OBJECT_SIZE(ap))
+        __CPROVER_OBJECT_SIZE(*(void **)&ap))
 
   {
     (void)va_arg(ap, int);
@@ -1822,7 +1822,7 @@ int __builtin___vsnprintf_chk(
   (void)*fmt;
 
   while((__CPROVER_size_t)__CPROVER_POINTER_OFFSET(*(void **)&ap) <
-        __CPROVER_OBJECT_SIZE(ap))
+        __CPROVER_OBJECT_SIZE(*(void **)&ap))
 
   {
     (void)va_arg(ap, int);