Explicitly decalre functions used in TorService.c to build with NDK 26+

[bitmold]

Android NDK toolchain 26 and 27 uses a newer version of clang that treats these implicitly invoked function calls as errors instead of warnings. since 25.2.9519653 is deprecated this is one of the things we need todo in order to use a supported NDK toolchain

[n8fr8]

@eighthave thoughts?

[bitmold]

If you stick to using NDK 25.2.9519653 which the CI uses and the scripts in tor-android recommends this won't be a problem (you just get compiler warnings), when working on code changes in tor-android I used a newer NDK by accident (27.0.11718014) and realized that tor no longer compiles due to NDK upgrading to clang 16:

https://www.redhat.com/en/blog/new-warnings-and-errors-clang-16

Of course, this code still compiles with the older clang/ndk that guardian project uses to release tor-android.

[bitmold]

Specifically clang throws out -Wimplicit-function-declarations on the functions tor_free_all from tor code itself (declared in shutdown.h) and unset_owning_controller_socket.

guardianproject/tor-android#57

but for that matter, both were introduced to stop gap fix a crash tor had on Android with comments in guardian project's fork of tor indicating that this code was to be removed once an upstream fix was introduced in tor itself. I've only kind of cursorily researched the issue tracker on the tor codebase, but @eighthave I'm curious to know if this is still needed at all.

[bitmold]

@n8fr8 Ideally this can be merged in before uniqx's work with #8 since releases to the tor fork are so infrequent. the remaining work to support a modern ndk toolchain is just done on the tor-android project

[syphyr]

The commit fixes the build issue with Tor and NDK 26
syphyr@75d99f8

Although, I still can't figure out why the jni in Tor is not included in libtor.so after updating to NDK 26.

[uniqx]

I've successfully finished a build of tor-android with these changes using ndk 25.2.9519653. So I think this is safe to merge.