Unbreak on powerpc64.

PR:		231722
Submitted by:	Piotr Kubaj
Approved by:	portmgr (tier-2 blanket)

math/gringo/Makefile

@@ -3,8 +3,8 @@
 
 PORTNAME=	gringo
 DISTVERSION=	4.5.4
-PORTREVISION=	1
 DISTVERSIONSUFFIX=	-source
+PORTREVISION=	1
 CATEGORIES=	math devel
 MASTER_SITES=	SOURCEFORGE/potassco/${PORTNAME}/${PORTVERSION}
 
@@ -16,8 +16,6 @@ LICENSE_FILE=	${WRKSRC}/COPYING
 
 BUILD_DEPENDS=	re2c:devel/re2c
 
-BROKEN_powerpc64=	fails to compile: term.cc: error: pow is not a member of std
-
 USES=		bison compiler:c++11-lib python:2.7 scons
 MAKE_ARGS=	${MAKE_ENV}
 CXXFLAGS+=	-std=c++11

math/gringo/files/patch-libgringo_src_term.cc

@@ -0,0 +1,10 @@
+--- libgringo/src/term.cc.orig	2018-09-25 16:02:56 UTC
++++ libgringo/src/term.cc
+@@ -21,6 +21,7 @@
+ #include "gringo/term.hh"
+ #include "gringo/logger.hh"
+ #include "gringo/graph.hh"
++#include <cmath>
+ 
+ namespace Gringo {
+