science/mbdyn: FIx build with clang16 by adding USE_CXXSTD

Reported by:	fallout

science/mbdyn/Makefile

@@ -11,7 +11,7 @@ WWW=		https://www.mbdyn.org/
 LICENSE=	GPLv2
 LICENSE_FILE=	${WRKSRC}/COPYING
 
-BROKEN_powerpc=		Does not compile on powerpc
+BROKEN_powerpc=		does not compile on powerpc
 
 BUILD_DEPENDS=	libatomic_ops>0:devel/libatomic_ops
 LIB_DEPENDS=	libltdl.so:devel/libltdl \
@@ -20,6 +20,7 @@ LIB_DEPENDS=	libltdl.so:devel/libltdl \
 
 USES=		compiler:c++11-lib fortran gmake libtool:build localbase
 USE_LDCONFIG=	yes
+USE_CXXSTD=	c++14 # fix build breakage with clang16 due to use of deprecated feature 'dynamic exception specifications', see https://public.gitlab.polimi.it/DAER/mbdyn/-/issues/339
 
 CPPFLAGS+=	-fpermissive -I${LOCALBASE}/include/suitesparse