[FR] ndk-build support for order file generation

### Description

Order files (much like PGO) need to be handled in steps of build instrumented -> run -> rebuild. Order files have some annoying requirements like not using `-O0` and other flag juggling as well. We could add a `LOCAL_ORDERFILE` and `NDK_GENERATE_ORDER_FILES` (the second being a command line option) to make that workflow a bit more obvious.

Start by tracing ndk-build’s existing PGO and instrumented-build workflow, then examine how order-file generation and optimization flags are currently handled. Define how LOCAL_ORDERFILE and NDK_GENERATE_ORDER_FILES should support the instrument-run-rebuild cycle, including the required flag changes; done means that workflow is exposed clearly through ndk-build.

Written by the indexing model from the issue text.