https://github.com/google/protobuf/issues/4887

* Enable ignoring unknown in json parsing in php

* Update generated descriptor files

* Update failure list for other languages.

* Remove unnecessary php files

Fix cpp benchmark dependency on mac

Merge 3.6.x into master

Fix initialization with Visual Studio

protoc-artifacts: Update centos base from 6.6 to 6.9

This avoids the need to use "yum update && yum upgrade" in the container
to be able to contact GitHub, which requires TLS 1.2[1].

I have verified that binaries built with this container still run in the
previous container; no errors like "/lib64/libc.so.6: version
`GLIBC_2.14' not found", which occur if using too new of a glibc when
compiling. CentOS 6.6 has glibc version 2.12 release 1.209.el6. CentOS
6.9 has glibc version 2.12 release 1.149.el6. Both would upgrade to
release 1.212.el6 via "yum update && yum upgrade".

1. https://githubengineering.com/crypto-deprecation-notice/

Updated Docker setup to use GCC 4.8

It appears that Visual Studio does not work well with std::once_flag
because it has a bug causing it to initialize that during dynamic
initialization instead of constant initialization. This change works
around the problem by using function static initializers instead.

@gerben-s originally wrote this change for the Google-internal codebase
but I am just cherry-picking it here.

This fixes #4773.

Fix SFINAE in 'RepeatedPtrFieldBase::Add'

Now that we depend on C++11, we need at least GCC 4.8 instead of 4.7.
This change updates the Docker setup to continue using CentOS 6.6 but
with GCC 4.8.

I also added libm to the whitelist for dynamically linked libraries for
the ARM64 protoc binary.

Without this the error of un-moveable GenericTypeHandler will pop until
'TypeHandler::New(arena_, std::move(value))' is called.

* Update message_module.cc

Add missing piece from pull request #4698:  actually initialize the new API object.

* Update message_module.cc

Fix bazel build of examples.

Add global extension registry to the repo.

* Add continuous test for ruby 2.3, 2.4 and 2.5

* Change ruby 2.5 to 2.5.0

* No need to provide argument to rb_funcall when argc is 0

* Fix tests for ruby 2.5

* Use rescue instead of assert_raise to accept subclass of error

Handle srcs in generated files by cd'ing in and out

Ruby JSON encoding omits zero-length repeated fields by default.

Feat: add import-style=commonjs_strict option to the compiler

Google::Protobuf::Struct can access a missing key (#3846)

Missing symbol exports for Windows DLL

Remove write-strings warning from COPTs

Add wsrpc

This should fix https://github.com/google/protobuf/issues/4717

This fixes issue #2610.

This was originally fixed in a101fa52 , but got
reverted by d36c0c53

Fix to allow a compilation under mips big endian with gcc

Internal convert file was broken. Change the capsule to the correct name

This change reduces the excessive warnings when compiling C++ protobufs like "external/protobuf_archive/python/google/protobuf/pyext/message.cc:2629:1: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings]"

The __MIPSEL__ is mips little endian, specific and we needed
to compile for a big endian mips target that also happened
to be a mips64, so replaced the __MIPSEL__ with a __mip__
which should preserve the build on little endian and allow a
build for a big endian setup.

	$ echo | mips64-linux-gcc -E -dM -
	... snip snip ...
	#define __mips__ 1
	#define __MIPSEB__ 1
Signed-off-by: Charles Hardin <ckhardin@gmail.com>

* Add -Og to no-warning-test

* Initialize value

* Implement PrintFieldName in CompactRepeatedFieldPrinter to prevent Woverloaded-virtual

* Update generated code

* This allows for ruby code to catch and handle Protobuf
    TypeErrors separately from the standard Ruby TypeError

  * Maintains backwards compatibility by having the new
    Google::Protobuf::TypeError inherit from the base
    TypeError. Any code that was catching TypeError should
    continue to work.