Should match b_lundef in meson(1).

Use a version script (matches Linux).

Index: src/meson.build
--- src/meson.build.orig
+++ src/meson.build
@@ -98,12 +98,9 @@ else
 endif
 
 gvnc_link_args = []
-if meson.get_compiler('c').has_link_argument('-Wl,--no-undefined')
-  gvnc_link_args += ['-Wl,--no-undefined']
-endif
 
 gvnc_syms = join_paths(meson.current_source_dir(), 'libgvnc_sym.version')
-if host_machine.system() == 'linux'
+if host_machine.system() == 'linux' or host_machine.system() == 'openbsd'
   gvnc_link_args += ['-Wl,--version-script,' + gvnc_syms]
 endif
 
@@ -189,9 +186,6 @@ if libpulse_dep.found()
   ]
 
   gvncpulse_link_args = []
-  if meson.get_compiler('c').has_link_argument('-Wl,--no-undefined')
-    gvncpulse_link_args += ['-Wl,--no-undefined']
-  endif
 
   gvncpulse_syms = join_paths(meson.current_source_dir(), 'libgvncpulse_sym.version')
   if host_machine.system() == 'linux'
@@ -351,9 +345,6 @@ endforeach
 
 
 gtk_vnc_link_args = []
-if meson.get_compiler('c').has_link_argument('-Wl,--no-undefined')
-  gtk_vnc_link_args += ['-Wl,--no-undefined']
-endif
 
 gtk_vnc_syms = join_paths(meson.current_source_dir(), 'libgtk-vnc_sym.version')
 if host_machine.system() == 'linux'