* win32_nat.c (cygwin_load_start): New variable.

* win32_nat.c (cygwin_load_start): New variable.
(cygwin_load_end): Ditto.
(have_saved_context): Ditto.
(saved_context): Ditto.
(max_dll_name_len): Delete obsolete variable.
(do_win32_fetch_inferior_registers): Use context saved from cygwin1.dll if we
are in a cygwin signal rather than a windows signal.
(solib_symbols_add): Detect and store beginning and end of cygwin DLL if dll
being loaded is the cygwin DLL.
(register_loaded_dll): Remove calculation of max_dll_name_len.
(win32_clear_solib): Ditto.
(handle_load_dll): Delete obsolete variable.  Remove unneeded call to
solib_add.
(handle_output_debug_string): Detect and store signal information sent by
Cygwin here.
(handle_exception): Silently pass on errors in the cygwin DLL.  Return -1 on
first pass exception.
(win32_continue): Remove spurious clearing of continue_status.
(get_win32_debug_event): Deal differently first chance exception.