misc.c: Fix overflow detection zombie in function grow_memory_block

Started out with this warning:
> src/misc.c: In function ‘grow_memory_block’:
> src/misc.c:333:25: error: comparison of unsigned expression in ‘< 0’ is always false [-Werror=type-limits]
>   333 |             if (new_cap < 0) {  // Overflow
>       |                         ^

1 files changed, 5 insertions, 4 deletions

diff --git a/src/misc.c b/src/misc.c
index b937075..fdebff9 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -19,6 +19,7 @@
 
 #include "misc.h"
 #include <stdarg.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -328,12 +329,12 @@ void grow_memory_block(struct memory_block *a, size_t amount)
             if (new_cap == 0) {
                 new_cap = 8;
             } else {
+                if (new_cap > SIZE_MAX / 2) {
+                    fprintf(stderr, "Memory block too large.");
+                    abort();
+                }
                 new_cap *= 2;
             }
-            if (new_cap < 0) {  // Overflow
-                fprintf(stderr, "Memory block too large.");
-                abort();
-            }
         }
         a->ptr = (char *)realloc(a->ptr, new_cap);
         a->capacity = new_cap;