strncat method
Implementation
void strncat(MemoryPointer dest, MemoryPointer src, int n) {
final destLen = strlen(dest);
final copyLen = strlen(src).clamp(0, n);
dest.copyBytesFrom(src, copyLen, destOffset: destLen);
dest.offsetBy(destLen + copyLen).fillBytes(0, 1); // terminator
}