D7444: setup: conditionalize access to `sys.dllhandle` when building extensions

[mharbison72 (Matt Harbison)]

mharbison72 added a comment.


  In D7444#109357 <https://phab.mercurial-scm.org/D7444#109357>, @indygreg wrote:
  
  > As for the output issues, I'm not sure what's going on. I added support for `Py_LegacyWindowsStdioFlag` to PyOxidizer a few hours ago. I'd start there. Feel free to make noise on PyOxidizer's issue tracker!
  
  That did the trick, and now I've got a usable (so far) oxidized binary.
  
  What do you think about this in `hg debuginstall`:
  
      File "mercurial.debugcommands", line 1486, in debuginstall
        os.path.dirname(pycompat.fsencode(os.__file__)),
    AttributeError: module 'os' has no attribute '__file__'
  
  That's not really a resource, so just special case it to print the exe?  (This is trying to print the equivalent of this: `checking Python lib (C:\Program Files\Python37\lib)...`)  There's also similar not-quite-resources use of __file__ in service of `hg extensions`, for example.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7444/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7444

To: mharbison72, #hg-reviewers, indygreg
Cc: indygreg, mercurial-devel