added null check to destructors

src/collections/HashMap.c

@@ -22,6 +22,9 @@ void HashMap_construct_size(HashMap_* ptr, u32 value_t_size, FreeFunction NULLAB
 }
 
 void HashMap_destroy(HashMap_* ptr){
+    if(!ptr)
+        return;
+
     for(u32 i = 0; i < ptr->height; i++){
         HashMapBucket* bu = &ptr->table[i];
         u32 len = List_len(&bu->key_hash_list, KeyHash);

src/string/StringBuilder.c

@@ -1,6 +1,9 @@
 #include "tlibc/string/StringBuilder.h"
 
 void StringBuilder_destroy(StringBuilder* b){
+    if(!b)
+        return;
+
     free(b->buffer.data);
     b->buffer = List_construct_size(NULL, 0, 0);
 }