RtlUpperChar

INT8 __stdcall RtlUpperChar(INT8 Character){
  RtlpIsUtf8Process(0);
  if( (unsigned __int8)(Character - 97) <= 0x19u )
    return Character ^ 0x20;
  return Character;
}

Referenced by:

RtlCompareString
RtlEqualString
RtlPrefixString