Don't USE_SLEDGEHAMMER=GCC-3.4 on 4.x when removing an unsupported warning

option from configure's CFLAGS lets this build with gcc 2.95 just fine.

While here, increase the chance of this working on alpha by making the
addition of -mieee not exclusive to *alpha*-*-linux*.

graphics/graphviz/Makefile

@@ -63,12 +63,11 @@ USE_LDCONFIG=	${PREFIX}/lib/${PORTNAME}
 .include <bsd.port.pre.mk>
 .include "${PORTSDIR}/misc/ldconfig_compat/bsd.ldconfig.mk"
 
-.if ${OSVERSION} < 500000
-USE_GCC=	3.4+
-.endif
-
 post-patch:
 	@${FIND} ${WRKSRC} -name Makefile.in | ${XARGS} ${REINPLACE_CMD} -e 's|(libdir)/pkgconfig|(prefix)/libdata/pkgconfig|'
+.if ${OSVERSION} < 500000
+	@${REINPLACE_CMD} 's|-Wno-unused-parameter||g' ${WRKSRC}/configure
+.endif
 
 post-install: install-ldconfig-file
 .if !defined(NOPORTDOCS)

graphics/graphviz/files/patch-configure

@@ -1,5 +1,14 @@
 --- configure.orig	Sun Aug 28 15:09:28 2005
-+++ configure	Wed Dec 28 16:15:47 2005
++++ configure	Sat Jan 28 22:36:22 2006
+@@ -4690,7 +4690,7 @@
+ 	        *-dec-osf* )
+ 	            CFLAGS="${CFLAGS} -mieee -Wall"
+ 	            ;;
+-                *alpha*-*-linux* )
++                *alpha*-*-* )
+                     CFLAGS="${CFLAGS} -mieee -Wall"
+                     ;;
+ 	        *-apple-darwin* )
 @@ -23372,21 +23372,21 @@
  fi
  fi