GNU LD accepts both. CMake seems to use the former than the latter.
llvm-svn: 227144
HelpText<"Do not allow undefined symbols from dynamic"
" library when creating executables">,
Group<grp_resolveropt>;
-def allow_shlib_undefs : Flag<["--"], "allow-shlib-undefined">,
+def allow_shlib_undefs : Flag<["-", "--"], "allow-shlib-undefined">,
HelpText<"Allow undefined symbols from dynamic"
" library when creating executables">,
Group<grp_resolveropt>;