gcs fix for internal error on Winnt/Alpha

[Jeffrey A Law]

  In message < 19971113135153.06746@dot.cygnus.com >you write:
  > Thu Nov 13 13:45:39 1997  Richard Henderson  <rth@cygnus.com>
  > 
  > 	* alpha.c (call_operand): Any reg is valid for WinNT.
  > 	* alpha.md (call_nt, call_value_nt): Don't force address into $27.
  > 	(anon nt calls): Add 'R' alternative.
  > 	* alpha/win-nt.h (TRAMPOLINE_TEMPLATE, TRAMPOLINE_SIZE,
  > 	INITIALIZE_TRAMPOLINE): Handle lack of original $27 and 32-bit ptrs.
Thanks.  Installed.

jeff