This issue is to add "make touch" to the 2.7 Makefile as suggested by Nick Coghlan in the following comment to issue 15964: "We should be able to add the "make touch" target to the 2.7 Makefile without running afoul of the "no new features" rule." (from http://bugs.python.org/issue15964#msg171001 ) This will make it easier to help people address certain build errors encountered when switching between 2.7 and 3.x branches.
I'm not so sure it's worth adding it. ISTM that this would be useful only to people that already encountered the problem described in #15964 and now that `make touch` is the solution. All the others will have to google for a solution anyway, and there's no much difference in finding `make touch` or `touch Include/Python-ast.hPython/Python-ast.c`
The idea is to make the solution consistent, regardless of which branch you have checked out (in 3.x, the list of files to touch is longer and "make touch" already exists)