waf-samba: Link with --undefined-version

wafsamba generates version scripts that name symbols which may not
exist in the library: _end, __bss_start and _edata are always listed as
local, and the per-version nodes carry symbols from older ABI signature
files that were later removed (e.g. tdb_do_delete). GNU ld ignores
these, but lld rejects them by default:

  ld.lld: error: version script assignment of 'local' to symbol '_end'
  failed: symbol not defined

meta-clang used to add -Wl,--undefined-version for libtalloc, libtdb,
libtevent, libldb and samba. Since the scripts are generated by design
this way, do it once in the class for all its users; binutils accepts
the option too. FreeBSD ports do the same for talloc and tdb.

Tested: libtalloc, libtdb, libtevent, libldb ptest images pass on
qemux86-64 with clang/lld; samba builds.

AI-Generated: Uses Claude Code
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-networking/classes/waf-samba.bbclass

@@ -24,6 +24,10 @@ CONFIGUREOPTS = " --prefix=${prefix} \
 # avoids build breaks when using no-static-libs.inc
 DISABLE_STATIC = ""
 
+# wafsamba version scripts name symbols that may not exist (_end, __bss_start,
+# _edata, and symbols from older ABI versions); lld rejects those by default
+LDFLAGS += "-Wl,--undefined-version"
+
 def get_waf_parallel_make(d):
     pm = d.getVar('PARALLEL_MAKE')
     if pm: