meson: Map host_system android to linux

This appears to be what is missing to support builds on Android (with
meson).

Author: Andres Freund <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/CAC7zN94TdsHhY88XkroJzSMx7E%3DBQpV9LKKjNSEnTM04ihoWCA%40mail.gmail.com

Author: petere

meson.build

@@ -184,6 +184,10 @@ sema_kind = 'sysv'
 if host_system == 'dragonfly'
   # apparently the most similar
   host_system = 'netbsd'
+elif host_system == 'android'
+  # while android isn't quite a normal linux, it seems close enough
+  # for our purposes so far
+  host_system = 'linux'
 endif
 
 # meson's system names don't quite map to our "traditional" names. In some