res_search: fix for aarch64

On linux_aarch64 `res_search` is `__res_search@GLIBC_2.17`, which is
different from the x86_64 counterpart `__res_search@GLIBC_2.2.5`.

Also fix tests.

test/cgo/BUILD

@@ -6,7 +6,6 @@ go_library(
     name = "cgo_lib",
     srcs = ["cgo.go"],
     cgo = True,
-    clinkopts = ["-lresolv"],
     importpath = "git.sr.ht/~motiejus/bazel-zig-cc/test/cgo",
     visibility = ["//visibility:private"],
 )

test/cgo/cgo.go

@@ -1,13 +1,8 @@
 package main
 
-// #define _FILE_OFFSET_BITS 64
-// #include <unistd.h>
-// #include <fcntl.h>
 // #include <stdio.h>
-// #include <resolv.h>
 // char* hello() { return "hello, world"; }
-// void phello() { printf("%s, your lucky numbers are %p and %p\n", hello(), fcntl, res_search); }
-// #cgo LDFLAGS: -lresolv
+// void phello() { printf("%s\n", hello()); }
 import "C"
 
 func main() {