libc: Add strxfrm()

libs/libc/include/string.h

@@ -74,6 +74,9 @@ extern "C"
     /* Compares a and b based on the current locale. */
     int strcoll(const char* a, const char* b);
 
+    /* Transforms src based on the current locale and stores n bytes of it in dest. */
+    size_t strxfrm(char* dest, const char* src, size_t n);
+
     /* Searches for the needle string in the haystack string. */
     char* strstr(const char* haystack, const char* needle);
 

libs/libc/src/string.cpp

@@ -136,6 +136,12 @@ extern "C"
         return strcmp(a, b);
     }
 
+    size_t strxfrm(char* dest, const char* src, size_t n)
+    {
+        strncpy(dest, src, n);
+        return n;
+    }
+
     size_t strcspn(const char* str, const char* reject)
     {
         const char* s = str;