Optimization for layout_init()

* Add missing files under benchmarks/ to the dist

* fix typo

* Sync upb

* https://github.com/protocolbuffers/upb/pull/208

* Fix php c extension compiling

Don't use macros defined by upb

* Update ruby conformance failure list

Enums use varint, so if the value is negative it should end up being longer.

This was caught my new conformance test cases.

Update versions to 3.9.1

Removed ByteCountInt64.  This is a transitional typedef that should n…

* Test singular fields are encoded in canonical way

* Defautl values in proto3 should not be encoded.
* Values should be converted to the canonical representation (e.g.,
long int64 value may be truncated for int32 field)

* Update failure list

* Update failure list

clang-cl requires the order to be the opposite of what it currently is.
It should not affect other compilers since this is the only compiler
that has both macros defined.

Down integrate internal changes to GitHub

Update to Truth 1.0

The previous issue of mktime doesn't work on Mac has been fixed.

We were creating a map decoding frame when starting the *map*,
but clearing the GC slot when finishing each *map entry*.  This
means that the decoding frame could be collected in the meantime.

* Add source code URI to the Ruby gemspec file

As a developer, I would like to easily find the source code origin for this gem when browsing through https://rubygems.org/gems/google-protobuf.
In order to solve this, I've followed instructions at https://guides.rubygems.org/specification-reference/#metadata by adding the source_code_uri metadata key pair.

* Use git tag instead of fixed "master" string

* Substitute the string, not the Gem::Version

Proto2 has been tested for invalid cases. Check implementation of
ExpectParseFailureForProto (https://github.com/protocolbuffers/protobuf/blob/master/conformance/binary_json_conformance_suite.cc#L322)

Fix for race in lazy initialization of handlers.

Optimized layout_mark() for Ruby

This fixes https://github.com/protocolbuffers/protobuf/issues/6532.

Archive is declared in the protobuf_deps() call above

When the @six//:six library is used on a target without the
`legacy_create_init` flag disabled, the library will not be
usable due to __init__.py being empty and the six code will
be in six.py. This change forces six to occupy the __init__
name, preventing this file getting created regardless of
the `legacy_create_init` setting.

See comments on a74c43bb for
context:
https://github.com/protocolbuffers/protobuf/commit/a74c43bbd906a42b6bf70668c5d515c6f1d8d2cb

Signed-off-by: DNKpp <dnkpp2011@gmail.com>

* Rolled forward again with "Updated upb from defcleanup branch..."

Revert "Revert "Updated upb from defcleanup branch and modified Ruby to use it (#5539)" (#5848)"

This reverts commit 1568deab.

* A few more merge fixes.

* Updated for defcleanup2 branch.

* Fixed upb to define upb_decode().

* Fixed names of nested messages.

* Revert submodule.

* Set -std=gnu90 and fixed warnings/errors.

Some of our Kokoro tests seem to run with this level of warnings,
and the source strives to be gnu90 compatible.  Enforcing it for
every build removes the possibility of some errors showing up in
Kokoro/Travis tests only.

* Fixed remaining warnings with gnu90 mode.

I tried to match warning flags with what Ruby appears to do
in our Kokoro tests.

* Initialize values registered by rb_gc_register_address().

* Fixed subtle GC bug.

We need to initialize this marked value before creating the instance.

* Truly fix the GC bug.

* Updated upb for mktime() fix.

* Removed XOPEN_SOURCE as we are not using strptime().

* Removed fixed tests from the conformance failure list for Ruby.

* Fixed memory error related to oneof def names.

* Picked up new upb changes re: JSON printing.

* Uncomment concurrent decoding test.