fix darwin redefinition warning

[Richard Henderson]

        * config/darwin.h (DARWIN_REGISTER_TARGET_PRAGMAS): Rename from
        REGISTER_TARGET_PRAGMAS.
        * config/rs6000/darwin.h (REGISTER_TARGET_PRAGMAS): Redefine.

Index: darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.h,v
retrieving revision 1.27
diff -c -p -d -r1.27 darwin.h
*** darwin.h	18 May 2002 23:47:09 -0000	1.27
--- darwin.h	19 May 2002 02:26:04 -0000
*************** enum machopic_addr_class {
*** 622,631 ****
  #define ASM_PREFERRED_EH_DATA_FORMAT(CODE,GLOBAL)  \
    (((CODE) == 1 || (GLOBAL) == 0) ? DW_EH_PE_pcrel : DW_EH_PE_absptr)
  
! #define REGISTER_TARGET_PRAGMAS(PFILE)                          \
!   do {                                                          \
!     cpp_register_pragma (PFILE, 0, "mark", darwin_pragma_ignore);  \
!     cpp_register_pragma (PFILE, 0, "options", darwin_pragma_options);  \
!     cpp_register_pragma (PFILE, 0, "segment", darwin_pragma_ignore);  \
!     cpp_register_pragma (PFILE, 0, "unused", darwin_pragma_unused);  \
    } while (0)
--- 621,630 ----
  #define ASM_PREFERRED_EH_DATA_FORMAT(CODE,GLOBAL)  \
    (((CODE) == 1 || (GLOBAL) == 0) ? DW_EH_PE_pcrel : DW_EH_PE_absptr)
  
! #define DARWIN_REGISTER_TARGET_PRAGMAS(PFILE)				\
!   do {									\
!     cpp_register_pragma (PFILE, 0, "mark", darwin_pragma_ignore);	\
!     cpp_register_pragma (PFILE, 0, "options", darwin_pragma_options);	\
!     cpp_register_pragma (PFILE, 0, "segment", darwin_pragma_ignore);	\
!     cpp_register_pragma (PFILE, 0, "unused", darwin_pragma_unused);	\
    } while (0)
Index: rs6000/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/darwin.h,v
retrieving revision 1.19
diff -c -p -d -r1.19 darwin.h
*** rs6000/darwin.h	3 May 2002 12:09:34 -0000	1.19
--- rs6000/darwin.h	19 May 2002 02:26:05 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 237,239 ****
--- 237,242 ----
  /* For binary compatibility with 2.95; Darwin C APIs use bool from
     stdbool.h, which was an int-sized enum in 2.95.  */
  #define BOOL_TYPE_SIZE INT_TYPE_SIZE
+ 
+ #undef REGISTER_TARGET_PRAGMAS
+ #define REGISTER_TARGET_PRAGMAS DARWIN_REGISTER_TARGET_PRAGMAS