[Darwin, PPC] Handle GCC target pragma.

For compatibility with other members of the port.
Note, that we do not handle the longcall attribute, since longcall
is not required/used on current Darwin.

2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>

	* config/rs6000/darwin.h: Handle GCC target pragma.

From-SVN: r272603

gcc/ChangeLog

 2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>
 
+	* config/rs6000/darwin.h: Handle GCC target pragma.
+
+2019-06-23  Iain Sandoe  <iain@sandoe.co.uk>
+
 	* config/rs6000/darwin.h: (__PPC__, __PPC64__): New.
 
 2019-06-22  Jeff Law  <law@redhat.com>

gcc/config/rs6000/darwin.h

@@ -400,6 +400,7 @@ extern int darwin_emit_picsym_stub;
   do \
     { \
       DARWIN_REGISTER_TARGET_PRAGMAS(); \
+      targetm.target_option.pragma_parse = rs6000_pragma_target_parse; \
       targetm.resolve_overloaded_builtin = altivec_resolve_overloaded_builtin; \
     } \
   while (0)