Add support for linux-musl-s390x target

[uweigand]

This implements the rest of #571, after the "cb" part (ericsink/cb#21) is merged.

[ericsink]

The current failure is because e_sqlite3mc (which is a very recent addition to the cb build system) is not being built for musl-s390x. I am not sure what it would take to address this, so for now I will just Cc @utelle

[uweigand]

Looks like this seems to be the only change needed: ericsink/cb#22

[utelle]

The current failure is because e_sqlite3mc (which is a very recent addition to the cb build system) is not being built for musl-s390x. I am not sure what it would take to address this, so for now I will just Cc @utelle

Sorry for the late response. I was away from home. Obviously, the problem is not related to SQLite3 Multiple Ciphers itself, but to the build procedure in cb.cs. Maybe the build procedure could be improved by making the list of targets a global object, instead of defining it separately for each component (making it easy to forget to add new targets to all relevant lists). This would allow to change it for all components in sync.

[ericsink]

No worries. It turned out to be an easy fix.