make build reproducible for capstone_sys

[chenhdc]

Hi, we found libcapstone_sys.rlib varies from filesystem readdir order. Probably from the read_dir in

capstone-rs/capstone-sys/build.rs

Line 74 in 7c9a51f

read_dir(dir)

. fs::read_dir()'s behavior is platform-specific.
We found https://github.com/gyscos/zstd-rs/pull/162 resolves a similar issue in another lib. Please make build reproducible for capstone_sys.

[tmfink]

Fixed by #153

[chenhdc]

@tmfink when fix this issue， could publish a new release?

[tmfink]

@tmfink when fix this issue， could publish a new release?

capstone-sys v0.16.0 and capstone v0.12.0 were just published