Update to gawk-5.1.0

Changelog: http://git.savannah.gnu.org/cgit/gawk.git/tree/NEWS
amd64 and sparc64 testing by me
macppc testing by cwen@
octeon testing by jj
ok kn@ cwen@

lang/gawk/Makefile

@@ -1,9 +1,10 @@
-# $OpenBSD: Makefile,v 1.39 2019/12/18 00:36:46 bcallah Exp $
+# $OpenBSD: Makefile,v 1.40 2020/05/17 20:26:40 bcallah Exp $
 
 COMMENT=	GNU awk
 
-V=		5.0.1
+V=		5.1.0
 DISTNAME=	gawk-$V
+EXTRACT_SUFX=	.tar.xz
 CATEGORIES=	lang
 MASTER_SITES=	${MASTER_SITE_GNU:=gawk/}
 

lang/gawk/distinfo

@@ -1,2 +1,2 @@
-SHA256 (gawk-5.0.1.tar.gz) = YlvzcY4lqE3ESGE11ctTiBdGgjYscBB/0T8hVy9WA7s=
-SIZE (gawk-5.0.1.tar.gz) = 5981609
+SHA256 (gawk-5.1.0.tar.xz) = z1/qSsVmX9UXGvRxa6qy7/x2MGqVcpiNW6EHjxljgr0=
+SIZE (gawk-5.1.0.tar.xz) = 3154564