This reverts commit 37581380.

* Revert "Revert "Fix Ruby module name generation when the ruby_package option is used (#5735)""

This reverts commit bb211e85.

* add new files to Makefile.am

* add frozen checks

* Use rb_check_frozen

* Correct assertion on frozen error message

The second argument for the method assert_raise is the message
to show when the assertion fails. It does not check the error
object's message.
Add an additional assertion that does check the error's message.

* do frozen check first

* example with extra enum method

* update expected test output

* slight simplification

* add test for generated enum helpers

* move const helpers to c extension

* more explicit test

* more explicit test

* indent

* add foo test

* add check for _const suffix

* Update version number to 3.7.0

* Add php/releash.sh to Makefile.am

* Make cpp_distcheck exit on fail

This reverts commit 9638dcc3.

* fix module name generation and add tests

* fix existing tests

* support both package name styles

* add check for overflow

* de-nestify

* break long lines

* let repeated fields push arrays

* add varargs push

* better test

Signed-off-by: Xiang Dai <764524258@qq.com>

* Update version to 3.7.0

* Update version number for java bom

* add more descriptive error messages to init methods

* add type errors test to Makefile.am

* Use gnu for ruby build because strptime is provided by posix

* Move option to extconf.rb

* Remove unused code in Rakefile

* Add config files for kokoro test

* Use gnu 11

* Define _XOPEN_SOURCE

* Add gnu11 option

* Remove XOPEN

* Try base_cc_flags

* Try config_options

* Move time.h to top

* Try -D_XOPEN_SOURCE=700

* Define XOPEN_SOURCE directly

* Try extconf.rb

* Try CFLAGS

* Try ext.cross_config_options

* Make mac ruby release job fail on error

* Try again

* Try define _XOPEN_SOURCE in extconf.rb

* Try again

* Define __USE_XOPEN

* Remove 2.6.0

* No mingw

* Throw error on mingw

* Remove XOPEN_SOURCE in upb

* Add back mingw

* Remove comment

* Fix Any json encoding/decoding for ruby.

* Revert unnecessary changes

* Ruby nested msg caps

* nested types tests added

* test cases added for RubifyConstant

* extracted NestedMessage to TestNestedMessage

* removed nested tests with leading underscore

* extracted testLowercase to toplevel testLowercaseNested

Revert "Revert "Enable the ignore_unknown_field option in the Ruby unmarshal options" (#5511)" (#5533)

* Revert "Revert "Enable the ignore_unknown_field option in the Ruby unmarshal options" (#5511)"

This reverts commit be1716a6.

* Separate ruby conformance test on Mac

* Fix shell syntax

* Fix test

* Add ruby 2.6 gem build for linux

* Add docker hub organization

* Add ruby2.6 in cross compile targets

* Fix tests

* Check mac version

* No need to install php in preparation for mac

* Add ruby 2.6 test

* Fix broken tests

* Fix compatibility test

* Fix bundler version

* Use new docker image

* Fix broken test

* Use new docker image in ruby26 test

* Install ruby for mac

* Fix gem build for mac

* Update version to 3.7.0

* Change base ruby to 2.5.0

* Revert unnecessary changes

This adds the ability for the MRI Ruby library to optionally pass in a
ignore_unknown_fields option when decoding JSON. The functionality was
added upstream in upb, this change exposes that option.

Lower the severity of lower-case ruby enum to warning. Add conformance test for allow_alias with lower_case enums

* Fix most of the unused variable warnings in Ruby tests

* Add encoded_field_b back in tests/common_tests.rb

Given an argument, the previous implementation was off by one
(`.first(2)` would return 3 elements) compared to the `Enumerable#first`
method.

* Add ruby 2.3, 2.4 and 2.5 test for linux.

* Update kokoro files

* Add back commented gc test

* Fix gc_test failure

* Remove unused code

* Update ruby 2.5.0 to 2.5.1

* Update ruby 2.3 to 2.3.8

* Remove useless comment

* Replace assert_true/assert_false with assert, because they are not provided in newer version of test/unit

* Use rescue to handle exception subclass

* Commented out the require that caused gc_test failure.

* Commented out test

* Fix typo

This change only adds basic proto2 support without advanced features
like extensions, custom options, maps, etc.

The protoc binary now generates ruby code for proto2 syntax.
However, for now, it is restricted to proto2 files without advanced features
like extensions, in which case it still errors out.

This change also modifies the DSL to add proto messages to the DescriptorPool.
There is a new DSL Builder#add_file to create a new FileDescriptor. With this,
the generated ruby DSL looks something like:

Google::Protobuf::DescriptorPool.generated_pool.build do
  add_file "test.proto" do
    add_message "foo" do
      optional :val, :int32, 1
    end
  end
end