aclang.m4 problem (Cygwin + VC++)

[Lars J. Aas]

I've just upgraded our projects to CVS Autoconf and CVS Automake.
It works great on Unix, but on Cygwin, with the VC++ 6.0 compiler, it
stops on the "C++ compiler working" test, because it doesn't understand
that "conftest.cc" is a .cpp file so it defaults to "object file" type
and fails on "corrupted file".  We have to use the filename "conftest.cpp"
instead.  Will such a switch cause any problems on any other platforms?

  Lars J