Set hardtop_plat to hardtop to find out what, if anything, breaks

aclocal.m4

@@ -1113,46 +1113,8 @@ dnl Remove common automounter nonsense
 dnl
 hardtop=`echo $hardtop | sed 's|^/tmp_mnt.*\(/local/.*\)$|\1|' | sed 's|^/tmp_mnt/|/|'`
 
-dnl Find 'hardtop_plat', the native format for 'hardtop'
-dnl (i.e., right kind of \dnl slashes on a Win32 box, but with b-slashes
-dnl being escaped).
-dnl
-dnl Note OSTYPE: On Cygwin we need to use 'cygpath' to convert
-dnl              /cygdrive/c/foo to c:/foo but we must not do that if we
-dnl              aren't building using Cygwin (notably msys), because
-dnl              cygpath doesn't exist.  It seems that 'bash' sets
-dnl              OSTYPE to 'cygwin' or 'msys' respectively, but cygwin's
-dnl              'sh' does not.  So we hackily assume that if the shell
-dnl              hasn't set it to 'msys' then we must be in Cygwin.
-dnl              Sigh.
-dnl
-dnl              The Right Thing is probably to test $BuildPlatform
-dnl              instead, but we are sloppy about setting that correctly
-dnl              at the moment, so we just work around for now.
-dnl
-dnl              The quotes round "$(OSTYPE)" are essential, for the
-dnl              Cygwin-sh case where OSTYPE is not set.
-case $HostPlatform in
-  i386-unknown-mingw32 | i386-unknown-cygwin32)
-        if test "${OSTYPE}" != "msys"
-          then
-            # convert $hardtop to a path that mingw will understand too
-            cyghardtop=${hardtop}
-            hardtop=`cygpath -w ${cyghardtop} | sed -e 's@\\\\@/@g'`
-            hardtop_plat=`cygpath -w ${cyghardtop} | sed -e 's@\\\\@\\\\\\\\@g'`
-          else
-dnl OK, so we're in the MSYS case.  hardtop looks like /c/....
-dnl We want to make hardtop_plat into c:/...
-dnl Stop using [] for quotes temporarily, so we can use [] in the sed regexp
-changequote(, )dnl
-               hardtop_plat=`echo ${hardtop} | sed -e 's@^/\\([a-zA-Z]\\)/@\\1:/@g'`
-changequote([, ])dnl
-        fi
-        ;;
-  *)
-        hardtop_plat=${hardtop}
-        ;;
-esac
+hardtop_plat="$hardtop"
+
 AC_SUBST(hardtop)
 AC_SUBST(hardtop_plat)