gnupg: fix the build on macppc with clang:

- add `-fheinous-gnu-extensions' as seen on some other archs
- add a patch to remove the `-Wa,-mppc' flag, because clang's
  integrated assembler was unhappy with it. Proposed by jca@,
  instead of using `-no-integrated-as'.

OK jca@ (maintainer)

security/gnupg/Makefile

@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.115 2019/07/12 02:16:23 visa Exp $
+# $OpenBSD: Makefile,v 1.116 2020/04/12 18:29:01 cwen Exp $
 
 COMMENT=	GNU privacy guard - a free PGP replacement
 
@@ -56,7 +56,8 @@ GNUPGDOCFILES=	README AUTHORS COPYING THANKS TODO BUGS \
 
 .include <bsd.port.arch.mk>
 .if (${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "mips64" || \
-     ${MACHINE_ARCH} == "mips64el") && ${PROPERTIES:Mclang}
+     ${MACHINE_ARCH} == "mips64el" || ${MACHINE_ARCH} == "powerpc") \
+     && ${PROPERTIES:Mclang}
 CFLAGS += -fheinous-gnu-extensions
 .endif
 

security/gnupg/patches/patch-mpi_config_links

@@ -0,0 +1,15 @@
+$OpenBSD: patch-mpi_config_links,v 1.7 2020/04/12 18:29:01 cwen Exp $
+
+Fix "error: unsupported argument '-mppc' to option 'Wa,'" with clang on macppc
+
+Index: mpi/config.links
+--- mpi/config.links.orig
++++ mpi/config.links
+@@ -234,7 +234,6 @@ case "${host}" in
+        echo '/* configured for {Open,Net}BSD on powerpc */' >>./mpi/asm-syntax.h
+        echo '#define ELF_SYNTAX'                 >>./mpi/asm-syntax.h
+        cat   $srcdir/mpi/powerpc32/syntax.h	 >>./mpi/asm-syntax.h
+-       mpi_sflags="-Wa,-mppc"
+        path="powerpc32"
+        ;;
+