reference: expand notation section

Also, move it after the language-model section.
repairs for when set_locale() always return NULL

... as it does on Android
add GC-stress mode

Stress mode forces a GC on every N allocation attempts, and it makes
JIT-generated code always take a slow path.

This mode uncovered only a bad test case and some boring start-up
bugs (boring because start-up is deterministic enough that they
never happen), so far.
configure: fix `ar' and `as' inference for cross-compile
work around Android dlsym() bug
add advice on cross-compiling for Android