[ffi] tree-shaking does not remove dependency .so library from the build

[makinghappen]

When building a project which includes a dependency having a native .so library linked via dart:ffi, it will be included in the resulting build even thou calls to that library were removed by tree-shaking dart code.

Flutter 3.11.0-0.1.pre • channel beta • https://github.com/flutter/flutter.git
Framework • revision 350d2c3a6c (8 weeks ago) • 2023-05-23 15:52:05 -0700
Engine • revision 7eca5cd1c5
Tools • Dart 3.1.0 (build 3.1.0-63.1.beta) • DevTools 2.23.1

[a-siva]

//cc @dcharkes

[dcharkes]

With DynamicLibrary.open, the path to the dynamic library is only known at runtime, so we cannot tree-shake.
We're working on an approach with which we know the dynamic libraries statically with @Native external functions. See #50565. This will enable us to tree-shake the native code in the future.

[a-siva]

@dcharkes should this issue also be listed in #50565 under items listed in refine core support