Darwin/MacOS X conftest file minor cleanup problem

[Bill Northcott]

At the end of each test compile autoconf macros endeavour to clean up  
the rubbish with a 'rm -f conftest.*'

The current Apple versions of gcc can build fat object files when  
given multiple -arch options as might be done with CFLAGS="-O2 -g - 
arch i386 -arch ppc"  Since not long after the libtool 1.5.22 release  
these -arch options have been correctly handled in libtool/autoconf  
build systems.

However, in order to build the fat binaries, the compiler driver  
creates a directory conftest.dSYM to hold the intermediate object  
files before they are combined with lipo.  The standard cleanup  
command does not remove this directory.

To reproduce this, take any autoconf package on MacOS or Darwin.  Set  
CFLAGS as above and run configure.

You will see lines in the log and console output like:
checking for ANSI C header files... rm: conftest.dSYM: is a directory
rm: conftest.dSYM: is a directory
yes

I presume this just needs a 'rm -rf'  in the appropriate place.

Bill Northcott