Release 0.40.1: Support for per target C/C++ standard flags.

[cgrindel]

As part of the march to our 1.0 release, we just added support for per-target C/C++ standard flags. Previously, you would need to manually specify the language standard flags in your .bazelrc file. Now, rules_swift_package_manager generates a separate target for each type of C-like source file that is found (e.g., C, C++, ObjC, ObjC++), sets the appropriate standard flag, and combines them into a Bazel target representing the underlying Swift package target. All of this should be transparent to clients, except that they should remove any --std= entries from their .bazelrc that were added to support the build of a Swift package dependency.

Important

If you use rules_xcodeproj in your project and you experience duplicate definition errors during the Xcode build, you will need to enable sandboxing for these builds. The firebase_example demonstrates how to do this. We plan to address this regression in an upcoming release.