Android/Termux pthread_cancel

[Devin Hussey]

Hello, I noticed a bit of an issue with Gnulib and Android when trying to compile nano on Termux.

Android, and by extension, Termux, is missing pthread_cancel, pthread_testcancel, pthread_setcancelstate, and pthread_setcanceltype.

A workaround is in https://github.com/cSploit/android.native/blob/master/bionic_workarounds.md, and a port is here https://github.com/tux-mind/libbthread, which is available in the Termux apt repo. (the former appears to be a port from glibc)

This causes, for example, regexec.c, to fail to build on Termux without using the bthread polyfill.

bthread provides <bthread.h> with -lbthread.