fixed typo

CMake: Update CXX Standard management

With this fix, Unity using IL2CPP should work with one of two
approaches:

- Call `FileDescriptor.ForceReflectionInitialization<T>` for every
  enum present in generated code (including oneof case enums)
- Ensure that IL2CPP uses the same code for int and any int-based
  enums

The former approach is likely to be simpler, unless IL2CPP changes
its default behavior. We *could* potentially generate the code
automatically, but that makes me slightly uncomfortable in terms of
generating code that's only relevant in one specific scenario. It
would be reasonably easy to write a tool (separate from protoc) to
generate the code required for any specific set of assemblies, so
that Unity users can include it in their application. We can always
decide to change to generate it automatically later.

Set ext.no_native = true for non mac platform

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.