Changed libc structure, shouldn't've added anything new

libc/string/strcat.c

@@ -0,0 +1,15 @@
+#include <string.h>
+
+char* strcat(char* str1, const char* str2) {
+    char* s = str1;
+    while (*s != '\0') { s++; }
+    strcpy(s, str2);
+    return str1;
+}
+
+char* strncat(char* str1, const char* str2, size_t n) {
+    char* s = str1;
+    while (*s != '\0') { s++; }
+    strncpy(s, str2, n);
+    return str1;
+}