gprof: disable building of a.out components

On arm64, riscv, and s390x disable building of aout components.
This allows gprof to build on these architectures which never supported
the legacy a.out binary format.

Obtained from:		s390x branch
MFC after:		3 months

usr.bin/gprof/Makefile

@@ -2,8 +2,14 @@
 #	$FreeBSD$
 
 PROG=	gprof
-SRCS=	gprof.c aout.c arcs.c dfn.c elf.c lookup.c hertz.c \
+SRCS=	gprof.c arcs.c dfn.c elf.c lookup.c hertz.c \
 	printgprof.c printlist.c kernel.c
+
+.if ${MACHINE_ARCH} != "aarch64" && ${MACHINE_ARCH} != "riscv" && \
+    ${MACHINE_ARCH} != "s390x"
+SRCS+=	aout.c
+CFLAGS+=	-DWITH_AOUT
+.endif
 FILES=	gprof.flat gprof.callg
 FILESDIR=	${SHAREDIR}/misc
 

usr.bin/gprof/gprof.c

@@ -160,8 +160,11 @@ main(int argc, char **argv)
 	 *	get information from the executable file.
 	 */
     if ((Kflag && kernel_getnfile(a_outname, &defaultEs) == -1) ||
-      (!Kflag && elf_getnfile(a_outname, &defaultEs) == -1 &&
-      aout_getnfile(a_outname, &defaultEs) == -1))
+      (!Kflag && elf_getnfile(a_outname, &defaultEs) == -1
+#ifdef WITH_AOUT
+      && aout_getnfile(a_outname, &defaultEs) == -1
+#endif
+      ))
 	errx(1, "%s: bad format", a_outname);
 	/*
 	 *	sort symbol table.

usr.bin/gprof/gprof.h

@@ -256,7 +256,9 @@ void		addarc(nltype *, nltype *, long);
 bool		addcycle(arctype **, arctype **);
 void		addlist(struct stringlist *, char *);
 void		alignentries(void);
+#ifdef WITH_AOUT
 int		aout_getnfile(const char *, char ***);
+#endif
 int		arccmp(arctype *, arctype *);
 arctype		*arclookup(nltype *, nltype *);
 void		asgnsamples(void);