* Rebuild python docker image

* Update docker image

* Change call to build_and_run_docker.sh

* Set up python tests for different versions

* Fix comments

Exclude command_line_interface_unittest.cc in MSVC build

* Fix benchmark to use docker image on kokoro

* Deleted pure php benchmark and fix long time benchmark

Removed Kokoro config for 64-bit Linux

This Kokoro configuration is no longer being used and the build.sh
script does not work anymore, so let's delete this configuration.

* Inherit from message instead of implement

When regestering class (implmenets other class) during MINIT, zend_class_implements
would call zend_class_entry->interface_gets_implemented(). In PHP-7.3 interface_gets_implemented shares the same location with create_object.
However, during MINIT, the global object storeage hasn't been initialized. And thus, caused segment fault in php 7.3.

* Use zend_string_init where interned string may be the value.
zend_string_dup will keep using the existing interned string.
In php 7.3, interned string cannot be destroyed from user's code.

* Uncommment debug code

* Use latest phpunit for each php versions

* Revert change in Dockerfile

* Update php test to use the new docker image

* Update composer

* Change docker organization

* Update phpunit

* Debug phpunit

* Store phpunit into bin dir in docker image

* Install valgrind to docker

* Fix compatibility test

* Remove generated_service_test from compatibility c extension test

* Update 32bit php test to the new docker image

* Install bison

* Fix build.sh

* Fix DOCKERIMAGE_PREFIX

* Fix basename

* Add comment to build_and_run_docker2.sh

* Remove commented code

* Fix comments

Some protos have enum values of "FOO" and "Foo", which the ObjC generation
then makes into the same thing. Just skip generating the enum element for
the duplicate as it would be a compile error because of the name collision.

The descriptors are still generated to support reflection and TextFormat
more completely.

Don't look up the TextFormat for the value as aliases can trip that
up, instead check the TextFormat names directly and then fetch the
value.

* Down-integrate internal changes

* Update generated code for php, objc and csharp.

* Add missing dependency in conformance_php

Replace update_version shell script with a python script

Replace update_version shell script with a python script, which is much better at handling XML rewrite. Update the PHP version too. As part of rewrite, some XML file format will change a little, but the semantics is still the same so it should be okay.

ObjC compiler changes to allow for easier import

Use docker for csharp, java_compatibility, and python_compatibility.

Use docker for csharp, java_compatibility, and python_compatibility. Remove prepare_build_linux_rc that is no longer needed.

By putting the NSAssert behind a DEBUG flag we aren't copying filepaths
into release builds.

Updated Bazel workspace in examples/ to handle zlib dependency

* Create a script to help update the version automatically

* Update comment in the update_version script

* Update script to fix special handling for common.h and Makefile.am

* Revise update_version script to only update the other constants in common.h if it is a major release. Reset Makefile.am version to 17:0:0

To make this work, I created a symlink to the existing zlib.BUILD file.
Maybe there is a better way to do this, but this is at least a quick
workaround to fix the build.

Make Protobuf compatible with C# 6

* Add Bazel config for optional zlib support

* Add hard dependency on zlib

* Remove unused config_setting

Windows: install missing headers

Fix TimestampPartial operator == overload implementation: Cannot call == inside it, otherwise it would cause stack overflow

fix: cmake install

Just like fields, some extension fieldnames can be named such that they appear
to have meaning to ARC. Add the annotation to the compiler will get things
correct.

Add a bunch of extensions to allow inspection on generation to ensure things
are correct.

This should help the Swift compiler if these apis are used because it
changes the codegen to not need copies/retains.

This should help the Swift compiler if these apis are used because it
changes the codegen to not need copies/retains.

For deprecated fields, identify the deprecated field and source file in the deprecation message. For deprecated files, identify the deprecated file in deprecation messages of generated interfaces. This additional context in deprecation messages will help provide developers with more context which could help them seek recommended alternatives to deprecated interfaces.