* php: Fixed php notices for unknown enum indices

* php: Fixed formatting of Duration

This fixes:
* Missing nanoseconds. The nanoseconds where divided as a float and
  implicitly converted to a string before being passed to bcadd.
  This can result in a float formatted in scientific/exponential notation,
  which bcmath doesn't understand.
* Durations are supposed to be formatted without trailing zeroes.

* Fix empty FieldMask json encoding/decoding

* Add failed test to python's conformance failure list

* Adopt upb change for timestamp and duration json to php

* Remove unused code

* Re-sync upb

* Fix php implementation timestamp json parsing

* Fix strptime use local timezone on mac.

* Remove succeeding tests

* Resync

* Add tests for values

* Fix php tests

* Fix encoder handlers change default value

Previously, oneofsubmsg_handler and submsg_handler change zval's default value directly.
The fix use REPLACE_ZVAL_VALUE which create a copy of parsed value and assign it to zval.

* Use legacy name in php runtime

Old generated code cannot work with new runtime, because the new runtime
assumes new class name for nested message. For details see #4738.

* Remove unused method

* uses namespaces for nested messages and enums

* fixes namespaces for PHP dist

* fixes namespace for Descriptors, adds Cardinality and Kind

* fixes nested namespaces for reserved words and adds tests

* adds tests and generator fix for php class prefixes

* fixes escaping of protobuf packages, enum comments, misc others

* nice refactor of generated code

* adds class files for backwards compatibility

* simplifies code with templates

* adds compatibility files to makefile

* cleanup of generator and fixes nested namespace bug

* regenerates proto types

* remove internal BC classes

* adds deprecated warning, adds methods back

* simplifies if statement

* fixes dist files

* addresses review comments

* adds back TYPE_URL_PREFIX constant

* adds @deprecated to old nested class files

* skips tests which require a separate process when protobuf.so is enabled

* Adds tests for legacy nested classes that do not require separate processes to test

* uses legacy names for GPBUtil message check

* adds block for IDE @deprecated message

* Namespace for nested message/enum in c extension

* Remove unused code

* uses namespaces for nested messages and enums

* fixes namespaces for PHP dist

* fixes namespace for Descriptors, adds Cardinality and Kind

* fixes nested namespaces for reserved words and adds tests

* adds tests and generator fix for php class prefixes

* fixes escaping of protobuf packages, enum comments, misc others

* nice refactor of generated code

* adds class files for backwards compatibility

* simplifies code with templates

* adds compatibility files to makefile

* cleanup of generator and fixes nested namespace bug

* regenerates proto types

* remove internal BC classes

* adds deprecated warning, adds methods back

* simplifies if statement

* fixes dist files

* addresses review comments

* adds back TYPE_URL_PREFIX constant

* adds @deprecated to old nested class files

* skips tests which require a separate process when protobuf.so is enabled

* Adds tests for legacy nested classes that do not require separate processes to test

* uses legacy names for GPBUtil message check

* adds block for IDE @deprecated message

* Namespace for nested message/enum in c extension

* Remove unused code

* Fix php well known type conformance tests

* Properly generate code for test.proto

* Provide GPBMetadata files in c extensions for generated files to import.

* Remove unnecessary test

* Clean up code

* Add declaration for initOnce.

* Refactoring

* Fix php well known type conformance tests

* Properly generate code for test.proto

* Provide GPBMetadata files in c extensions for generated files to import.

* Remove unnecessary test

* Clean up code

* Add declaration for initOnce.

* Refactoring

divideInt64ToInt32 is called statically from protobuf/php/src/Google/Protobuf/Internal/CodedOutputStream.php
(the only reference)
This causes fatal error in PHP 7.1 (32-bit only because 64-bit doesn't use this function)

* Add json encode/decode for php.

* Fix php conformance test on 32-bit machines.

* Fix conformance test for c extension.

* Fix comments

Update commit id to upload latest composer.
Compile php with bc-math for future json support.

* Follows proper autoloading standards
 - Splits PHP classes in descriptor.php into separate files
 - Splits MapFieldIter and RepeatedFieldIter into separate files
 - Moves descriptor.php to Internal/functions.php
 - Moves all namespaced functions into Iternal/functions.php

* fixes Makefile.am for added php files

* [PHP] moves all functions to GPBUtil

* removes description.php from the makefile

Accept regular PHP array for repeated/map setter. Existing map/repeated
field will be swapped by a clean map/repeated field. Then, elements in
the array will be added to the map/repeated field. All elements will be
type checked before adding.

See #2686 for detail.

* Down-integrate internal changes to github.

* Update conformance test failure list.

* Explicitly import used class in nano test to avoid random test fail.

* Update _GNUC_VER to use the correct implementation of atomic operation
on Mac.

* maps_test.js: check whether Symbol is defined before using it (#2524)

Symbol is not yet available on older versions of Node.js and so this
test fails with them. This change just directly checks whether Symbol is
available before we try to use it.

* Added well_known_types_embed.cc to CLEANFILES so that it gets cleaned up

* Updated Makefile.am to fix out-of-tree builds

* Added Bazel genrule for generating well_known_types_embed.cc

In pull request #2517 I made this change for the CMake and autotools
builds but forgot to do it for the Bazel build.

* Update _GNUC_VER to use the correct implementation of atomic operation on Mac.

* Add new js file in extra dist.

* Bump version number to 3.2.0

* Fixed issue with autoloading - Invalid paths (#2538)

* PHP fix int64 decoding (#2516)

* fix int64 decoding

* fix int64 decoding + tests

* Fix int64 decoding on 32-bit machines.

* Fix warning in compiler/js/embed.cc

embed.cc: In function ‘std::string CEscape(const string&)’:
embed.cc:51:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < str.size(); ++i) {
                                ^

* Fix include in auto-generated well_known_types_embed.cc

Restore include style fix (e3da722b) that has been trampled by
auto-generation of well_known_types_embed.cc

* Fixed cross compilations with the Autotools build

Pull request #2517 caused cross compilations to start failing, because
the js_embed binary was being built to run on the target platform
instead of on the build machine. This change updates the Autotools build
to use the AX_PROG_CXX_FOR_BUILD macro to find a suitable compiler for
the build machine and always use that when building js_embed.

* Minor fix for autocreated object repeated fields and maps.

- If setting/clearing a repeated field/map that was objects, check the class
  before checking the autocreator.
- Just to be paranoid, don’t mutate within copy/mutableCopy for the autocreated
  classes to ensure there is less chance of issues if someone does something
  really crazy threading wise.
- Some more tests for the internal AutocreatedArray/AutocreatedDictionary
  classes to ensure things are working as expected.
- Add Xcode 8.2 to the full_mac_build.sh supported list.

* Fix generation of extending nested messages in JavaScript (#2439)

* Fix generation of extending nested messages in JavaScript

* Added missing test8.proto to build

* Fix generated code when there is no namespace but there is enum definition.

* Decoding unknown field should succeed.

* Add embed.cc in src/Makefile.am to fix dist check.

* Fixed "make distcheck" for the Autotools build

To make the test pass I needed to fix out-of-tree builds and update
EXTRA_DIST and CLEANFILES.

* Remove redundent embed.cc from src/Makefile.am

* Update version number to 3.2.0-rc.1 (#2578)

* Change protoc-artifacts version to 3.2.0-rc.1

* Update version number to 3.2.0rc2

* Update change logs for 3.2.0 release.

* Update php README

* Update upb, fixes some bugs (including a hash table problem). (#2611)

* Update upb, fixes some bugs (including a hash table problem).

* Ruby: added a test for the previous hash table corruption.

Verified that this triggers the bug in the currently released
version.

* Ruby: bugfix for SEGV.

* Ruby: removed old code for dup'ing defs.

* Reverting deployment target to 7.0 (#2618)

The Protobuf library doesn’t require the 7.1 deployment target so
reverting it back to 7.0

* Fix typo that breaks builds on big-endian (#2632)

* Bump version number to 3.2.0

This pull request includes two implementation: C extension and PHP
package. Both implementations support encode/decode of singular,
repeated and map fields.