When lld is ld, install bfd's man page as ld.bfd.1

When WITH_LLD_IS_LD is set, lld's man page is installed as ld.1.gz, as
was GNU BFD's man page prior to this change.

Reported by:	Tobias Kortkamp
Sponsored by:	The FreeBSD Foundation

gnu/usr.bin/binutils/ld/Makefile

@@ -7,7 +7,15 @@ ELF_SCR_EXT=	x xbn xc xd xdc xdw xn xr xs xsc xsw xu xw
 .PATH: ${SRCDIR}/ld
 
 PROG=	ld.bfd
+.if ${MK_LLD_IS_LD} == "no"
 MAN=	ld.1
+.else
+MAN=	ld.bfd.1
+CLEANFILES+=	ld.bfd.1
+ld.bfd.1:	ld.1
+	${CP} ${.ALLSRC} ${.TARGET}
+.endif
+
 SCRIPTDIR= /usr/libdata/ldscripts
 SRCS+=	ldcref.c \
 	ldctor.c \