PATCH: Allow gcc/gthr* to be compiled by C++ as well as C

[Loren James Rittle <rittle at latour dot rsch dot comm dot mot dot com>]

Both libstdc++-v3/libsupc++/eh_alloc.cc and [...]/eh_globals.cc were
written to compile against the gcc/gthr.h abstraction layer, but the
configuration was hosed at some point and it now always maps to the
gcc/gthr-single.h configuration even if --enable-threads was provided
while configuring libstdc++-v3.  The upshot is that C++ EH is broken
in light of multi-threading.  This is a regression from 2.95.X on at
least some platforms.

Only the gcc/gthr-posix.h change has been fully bootstrapped on
multiple architectures.  Changes to other files are identical in form.

David originally caught this problem and provided a patch for
gthr-posix.h bundled in other work.  Approval for mainline and 3.0
branch is sought since the patch to actually fix libsupc++/eh_*.cc is
up next and requires this trivial patch.

2001-05-30  Loren J. Rittle  <ljrittle@acm.org>
	    John David Anglin  <dave@hiauly1.hia.nrc.ca>

	* gthr-posix.h (__gthread_active_ptr): Cast function pointer
	to target type to allow ISO C++ compiler to accept it.
	* gthr-dce.h (__gthread_active_ptr): Likewise.
	* gthr-solaris.h (__gthread_active_ptr): Likewise.

Index: gcc/gthr-dce.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/gthr-dce.h,v
retrieving revision 1.10
diff -c -r1.10 gthr-dce.h
*** gthr-dce.h	2001/05/26 01:31:34	1.10
--- gthr-dce.h	2001/05/30 11:14:11
***************
*** 79,85 ****
  #pragma weak pthread_yield
  #endif
  
! static void *__gthread_active_ptr = &pthread_create;
  
  static inline int
  __gthread_active_p (void)
--- 79,85 ----
  #pragma weak pthread_yield
  #endif
  
! static void *__gthread_active_ptr = (void *) &pthread_create;
  
  static inline int
  __gthread_active_p (void)
Index: gcc/gthr-posix.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/gthr-posix.h,v
retrieving revision 1.13
diff -c -r1.13 gthr-posix.h
*** gthr-posix.h	2001/05/26 01:31:34	1.13
--- gthr-posix.h	2001/05/30 11:14:11
***************
*** 75,81 ****
  #pragma weak pthread_setschedparam
  #endif
  
! static void *__gthread_active_ptr = &pthread_create;
  
  static inline int
  __gthread_active_p (void)
--- 75,81 ----
  #pragma weak pthread_setschedparam
  #endif
  
! static void *__gthread_active_ptr = (void *) &pthread_create;
  
  static inline int
  __gthread_active_p (void)
Index: gcc/gthr-solaris.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/gthr-solaris.h,v
retrieving revision 1.8
diff -c -r1.8 gthr-solaris.h
*** gthr-solaris.h	2001/05/26 01:31:34	1.8
--- gthr-solaris.h	2001/05/30 11:14:11
***************
*** 81,87 ****
  /* This will not actually work in Solaris 2.5, since libc contains
     dummy symbols of all thr_* routines. */
  
! static void *__gthread_active_ptr = &thr_create;
  
  static inline int
  __gthread_active_p (void)
--- 81,87 ----
  /* This will not actually work in Solaris 2.5, since libc contains
     dummy symbols of all thr_* routines. */
  
! static void *__gthread_active_ptr = (void *) &thr_create;
  
  static inline int
  __gthread_active_p (void)