Have these attriubtes set to 'true' or 'false'.

The back-end cannot differentiate between functions that are from a .ll file and
those generated from the front-end. We cannot then take the non-precense of
these attributes as a "false" value. Have the front-end explicitly set the value
to 'true' or 'false' depending upon what is actually set.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176985 91177308-0d34-0410-b5e6-96231b3b80d8