PHP namespaces for nested messages and enums (#4536)

* 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

1 files changed, 3 insertions, 3 deletions

diff --git a/php/tests/encode_decode_test.php b/php/tests/encode_decode_test.php
index 74d5526d..d36b883e 100644
--- a/php/tests/encode_decode_test.php
+++ b/php/tests/encode_decode_test.php
@@ -7,7 +7,7 @@ use Google\Protobuf\RepeatedField;
 use Google\Protobuf\GPBType;
 use Foo\TestEnum;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 use Foo\TestPackedMessage;
 use Foo\TestRandomFieldOrder;
 use Foo\TestUnpackedMessage;
@@ -82,7 +82,7 @@ class EncodeDecodeTest extends TestBase
         $n->mergeFromString($data);
         $this->assertSame('abc', $n->getOneofString());
 
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $sub_m->setA(1);
         $m->setOneofMessage($sub_m);
         $data = $m->serializeToString();
@@ -105,7 +105,7 @@ class EncodeDecodeTest extends TestBase
         $this->assertSame("oneof_string", $n->getMyOneof());
         $this->assertSame("", $n->getOneofString());
 
-        $sub_m = new TestMessage_Sub();
+        $sub_m = new Sub();
         $m->setOneofMessage($sub_m);
         $data = $m->serializeToString();
         $n = new TestMessage();