gogio: [iOS] link with -lresolv

Since Go 1.20 c-shared object files may lack a reference to the resolv
library and it must be added manually to the linking step.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

gogio/iosbuild.go

@@ -203,6 +203,7 @@ int main(int argc, char * argv[]) {
 		compile.Args = append(compile.Args,
 			"-Werror",
 			"-fmodules",
+			"-lresolv",
 			"-fobjc-arc",
 			"-x", "objective-c",
 			"-F", tmpDir,