OptionValueFileSpec had an accessor to read the contents of the file and...

OptionValueFileSpec had an accessor to read the contents of the file and return the data. This can end up being used to get the string contents of a text file and could end up not being NULL terminated. I added accessors to get the file contents raw, or with a null terminator. Added the needed calls to make this happen in the FileSpec and File classes.

llvm-svn: 162921