Add getAsUnquotedString
Add getAsUnquotedString

Add a method to return an Init as an unquoted string.  This primarily
affects StringInit where we return the value without surrounding it
with quotes.

This is in preparation for removing the ugly #NAME# hack and replacing
it with standard TabelGen operators.

git-svn-id: a4a6f32337ebd29ad4763b423022f00f68d1c7b7@137231 91177308-0d34-0410-b5e6-96231b3b80d8

lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx