fix: merge '-Wl,' with next value when (#4367) **What type of PR is this?** > Bug fix **What does this PR do? Why is it needed?** Previously if we pass `-extldflags,-Wl,--thread` into command line, it will only recognizes `-Wl` and ignores `--thread`. **Which issues(s) does this PR fix?** #3921 Fixes # If we see `-Wl`, we can merge with next value in the list. **Other notes for review** Co-authored-by: zhanning.lu <zhanning.lu@bytedance.com>