rsync: use xxhash

reminded by the dwz mail, rsync would also like to use xxhash if
available:

'The xxHash library (https://cyan4973.github.io/xxHash/) provides
extremely fast checksum functions that can make the "rsync algorithm"
run much more quickly, especially when matching blocks in large files.
Installing this development library adds xxhash checksums as the default
checksum algorithm. You'll need at least v0.8.0 if you want rsync to
include the full range of its checksum algorithms.'

while xxHash does provide standard shared+static libraries, it is more
commonly used as a "header-only library" (done here and also in dwz)
so there's no additional run dependency in rsync for this.

ok?

Index: Makefile
===================================================================
RCS file: /cvs/ports/net/rsync/Makefile,v
retrieving revision 1.97
diff -u -p -r1.97 Makefile
--- Makefile 5 Jan 2023 21:59:21 -0000 1.97
+++ Makefile 5 Jun 2023 11:36:48 -0000
@@ -1,6 +1,7 @@
COMMENT = mirroring/synchronization over low bandwidth links

DISTNAME = rsync-3.2.7
+REVISION = 0
CATEGORIES = net
HOMEPAGE = https://rsync.samba.org/

@@ -19,12 +20,12 @@ MODULES = lang/python

MODPY_RUNDEP = No

-BUILD_DEPENDS = textproc/py-commonmark${MODPY_FLAVOR}
+BUILD_DEPENDS = textproc/py-commonmark${MODPY_FLAVOR} \
+ sysutils/xxhash

SEPARATE_BUILD =Yes
CONFIGURE_STYLE =gnu
CONFIGURE_ARGS =--disable-lz4 \
- --disable-xxhash \
--disable-zstd \
--with-included-popt \
--with-included-zlib \
@@ -33,6 +34,8 @@ CONFIGURE_ARGS =--disable-lz4 \
--with-rsh=/usr/bin/ssh \
--with-nobody-user=_rsync \
--with-nobody-group=_rsync
+CONFIGURE_ENV +=CPPFLAGS="-I${LOCALBASE}/include -DXXH_INLINE_ALL=1" \
+ ac_cv_search_XXH64_createState=""

.include <bsd.port.arch.mk>

@@ -41,8 +44,7 @@ CONFIGURE_ARGS +=--enable-md5-asm
.endif

.if ${FLAVOR:Miconv}
-CONFIGURE_ENV +=CPPFLAGS='-I${LOCALBASE}/include' \
- LDFLAGS='-L${LOCALBASE}/lib'
+CONFIGURE_ENV +=LDFLAGS='-L${LOCALBASE}/lib'
LIB_DEPENDS += converters/libiconv
WANTLIB += iconv
.endif