From:
https://github.com/rake-compiler/rake-compiler/issues/146#issuecomment-368539245

The tests can run as what Apple calls a Logic Test (under xctest), which means
it doesn't have to load an full UI App under the simulator, which speeds things
up a fair amount.

Fix benchmark build

* Edited MessageFieldGenerator to clone to backing field instead of property

* Generated C# proto code

Cleanup + documentation for Java Lite runtime.

Fixed a Visual Studio 2017 build error. (#4488)

fix java benchmark, fix dashboard build

The current 15.6.x versions of Visual Studio 2017 contain a bug that
prevent them from compiling the following construct under certain
conditions:

std::unique_ptr<std::unique_ptr<Foo> []> foos;

This will fail to compile if Foo is an abstract class. To work-around
the problem the whole construct was change into:

std::vector<std::unique_ptr<Foo>> foos;

This not only fixes the compiler error but is also more readable than
previous version.

Add gogo benchmark

Add dashboard support  

The compiler and util subpackages are created by the build_py class in
setup.py. This has caused an issue in the protobuf package in
conda-forge (https://github.com/conda-forge/protobuf-feedstock/issues/40),
which is fixed by this commit.

The SampleEnumMethod method was previously only called via
reflection, so the Unity linker thought it could be removed. Ditto
the parameterless constructor in ReflectionHelper.

This PR should avoid that issue, reducing the work needed by
customers to use Google.Protobuf from Unity.

Fix problem: cmake build failed in c++11  by clang

[C#] Update test project to be used with dotnet test and Visual Studio Test Explorer

CMakeLists.txt adds c++11 flags for clang

* Fix setup.py for windows build.

* Bump version number to 3.5.2

* Cat the test-suite.log on errors for presubits

Improve error message when googletest is missing.

Add support for Power (ppc64le) arch

Cleaner protoc artifacts

Update instructions about getting protobuf source.

Move ObjC WKTs to minimal imports to avoid import cycle.

Since the generated header import GPBProtocolBuffers.h, there is no need
to generate imports for the WKTs as they will have already been imported.

To ensure all headers aren't dependent on other things being imported
before/after them, make a source that just imports each header and add
it to the unittesting target, that way we ensure it can be included on
its own with ordering issues.

Also do this testing with a few generated headers that aren't part of
the library to help ensure the different generated imports needed are
complete.