* shortcut.c: New file. Provides a C interface to reading of

Windows shortcuts to avoid compiler flag `-fvtable-thunks'.
        * shortcut.h: Ditto.
        * Makefile.in: Add shortcut.o to DLL_OFILES.
        * cygerrno.h: Provide a C interface to `geterrno_from_win_error' for
        using in shortcut.c.
        * errno.cc (geterrno_from_win_error): Define as extern "C".
        * path.cc (struct symlink_info): Remove methods `check_shortcut' and
        `check_sysfile'.
        (shortcut_header): Move to shortcut.c.
        (shortcut_initalized): Ditto.
        (create_shortcut_header): Ditto.
        (cmp_shortcut_header): Ditto.
        (symlink_info::check_shortcut): Ditto. Reorganize as a plain C function.
        (symlink_info::check_sysfile): Redefine as a global function using the
        same parameter list as `check_shortcut' for clearness.
        (symlink_info::check): Change parameter list for calls to
        `check_shortcut' and `check_sysfile'.

winsup/cygwin/shortcut.h

@@ -0,0 +1,28 @@
+/* shortcut.h: Hader file for shortcut.c
+
+   Copyright 2001 Red Hat, Inc.
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The header written to a shortcut by Cygwin or U/WIN. */
+#define SHORTCUT_HDR_SIZE	76
+
+extern char shortcut_header[];
+extern BOOL shortcut_initalized;
+
+extern void create_shortcut_header ();
+
+int check_shortcut (const char *path, DWORD fileattr, HANDLE h,
+		    char *contents, int *error, unsigned *pflags);
+
+#ifdef __cplusplus
+};
+#endif