lang/smlnj: Fix build with llvm16

- Pet portclippy

Approved by:	portmgr (blanket)
Sponsored by:	The FreeBSD Foundation

lang/smlnj/Makefile

@@ -21,17 +21,20 @@ ONLY_FOR_ARCHS=	amd64 i386
 
 USES=		compiler
 
-NO_WRKSUBDIR=	yes
-
 SUB_FILES=	pkg-install
 SUB_LIST=	EXEBINDIR=${MLBINRELATIVE} EXENAMES="${MLEXE}"
+
+NO_WRKSUBDIR=	yes
+
 PKGDEINSTALL=	${PKGINSTALL}
 
 OPTIONS_DEFINE=		EVERYTHING RECOMPILE
-RECOMPILE_IMPLIES=	EVERYTHING
+
 EVERYTHING_DESC=	install everything from the SML/NJ distribution
 RECOMPILE_DESC=		recompile the SML compiler - implies EVERYTHING
 
+RECOMPILE_IMPLIES=	EVERYTHING
+
 .include <bsd.port.pre.mk>
 
 # XXX see FreeBSD PR 247421
@@ -43,6 +46,10 @@ RUNTIME_SO=	"${STAGEDIR}${MLBIN}/.run/run.$${ARCH}-$${OPSYS}.so"
 PLIST_SUB+=	RUNTIME_SO=
 .endif
 
+.if ${COMPILER_TYPE} == clang && ${COMPILER_VERSION} >= 160
+CFLAGS+=	-Wno-error=incompatible-function-pointer-types
+.endif
+
 .if (${ARCH} == "i386")
 MLARCH=		x86
 MLSIZE=		32