* cygcheck.cc (dump_sysinfo): Fix multiple Cygwin DLL test.

* path.cc: Fetch mount points from fstab files instead of from
	registry.  Use adapted functions copied from Cygwin DLL.
	(mnt_t): Drop issys member.  Define as "mnt_t" instead of "struct mnt_t"
	subsequently.
	(max_mount_entry): New variable.
	(unconvert_slashes): Move to earlier location in file.  Make inline.
	(find2): Remove.
	(get_cygdrive0): Remove.
	(get_cygdrive): Remove.
	(skip_ws): New function.
	(find_ws): Ditto.
	(conv_fstab_spaces): Ditto.
	(read_flags): Ditto.
	(from_fstab_line): Ditto.
	(get_user): Ditto.
	(from_fstab): Ditto.
	(mnt_sort): Ditto.
	(read_mounts): Drop old registry code.  Fetch
	"Software\Cygwin\Setup\rootdir" value from HKCU or HKLM key.  Use
	rootdir extracted from module path as fallback.  Call from_fstab for
	nouser and user mount points.
	(setmntent): Check max_mount_entry to test if read_mounts must be
	called.
	(getmntent): Use MOUNT_SYSTEM flag instead of mnt_t's issys member.

winsup/utils/cygcheck.cc

@@ -1669,6 +1669,7 @@ dump_sysinfo ()
   if (givehelp)
     printf ("Looking for various Cygwin DLLs...  (-v gives version info)\n");
   int cygwin_dll_count = 0;
+  char cygdll_path[32768];
   for (pathlike *pth = paths; pth->dir; pth++)
     {
       WIN32_FIND_DATA ffinfo;
@@ -1686,7 +1687,11 @@ dump_sysinfo ()
 		  sprintf (tmp, "%s%s", pth->dir, f);
 		  if (strcasecmp (f, "cygwin1.dll") == 0)
 		    {
-		      cygwin_dll_count++;
+		      if (!cygwin_dll_count)
+		        strcpy (cygdll_path, pth->dir);
+		      if (!cygwin_dll_count
+			  || strcasecmp (cygdll_path, pth->dir) != 0)
+			cygwin_dll_count++;
 		      found_cygwin_dll = strdup (tmp);
 		    }
 		  else