[NFC] Fix typos in comments

  if (CurFnInfo->getMaxVectorWidth() > LargestVectorWidth)

    LargestVectorWidth = CurFnInfo->getMaxVectorWidth();

  // Add the required-vector-width attribute. This contains the max width from:

  // Add the min-legal-vector-width attribute. This contains the max width from:

  // 1. min-vector-width attribute used in the source program.

  // 2. Any builtins used that have a vector width specified.

  // 3. Values passed in and out of inline assembly.

  // 4. Width of vector arguments and return types for this function.

  // 5. Width of vector aguments and return types for functions called by this

  // 5. Width of vector arguments and return types for functions called by this

  //    function.

  if (getContext().getTargetInfo().getTriple().isX86())

    CurFn->addFnAttr("min-legal-vector-width",