rust_aconfig_library generates src/lib.rs and uses it to build library variants (dylib, rlib-rlib_std, and rlib-dylib_std) as of what `rust_library` produces
Test: go test
Change-Id: I6c4603691d4306c463c2e9521f5c11c30765b1e3
The generated module lets us keep the aconfig code in its own pacakge
and not infect all of the cc package with aconfig. It's also closer
to what bazel is going to do
Bug: 283479529
Test: m aconfig_hello_world_cc && adb push $TOP/out/target/product/panther/system/bin/aconfig_hello_world_cc /system/bin && adb shell aconfig_hello_world_cc
Change-Id: I2fb9e419939c7ca77b111da9c376af077e2348a9
Bug: 283910439
Test: m dist ; m all_aconfig_declarations ; gqui from all_aconfig_declarations.pb proto /source/aosp-master-with-phones/build/make/tools/aconfig/protos/aconfig.proto:android.aconfig.parsed_flags
Change-Id: Ia89c7f9c53fa1600fa2f9c8ea01319e949e09f58
Bug: 285303012
Test: for x in next trunk trunk_food trunk_staging ; do lunch aosp_panther-$x-eng ; m nothing ; done
Change-Id: I3375f46b3ecbbc516d1bee6ab3f80725fcccde8f