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, 138 insertions, 0 deletions

diff --git a/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php b/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php
new file mode 100644
index 00000000..c06a0a6e
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php
@@ -0,0 +1,138 @@
+<?php
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: google/protobuf/descriptor.proto
+
+namespace Google\Protobuf\Internal\DescriptorProto;
+
+use Google\Protobuf\Internal\GPBType;
+use Google\Protobuf\Internal\GPBWire;
+use Google\Protobuf\Internal\RepeatedField;
+use Google\Protobuf\Internal\InputStream;
+use Google\Protobuf\Internal\GPBUtil;
+
+/**
+ * Generated from protobuf message <code>google.protobuf.DescriptorProto.ExtensionRange</code>
+ */
+class ExtensionRange extends \Google\Protobuf\Internal\Message
+{
+    /**
+     * Generated from protobuf field <code>optional int32 start = 1;</code>
+     */
+    private $start = 0;
+    private $has_start = false;
+    /**
+     * Generated from protobuf field <code>optional int32 end = 2;</code>
+     */
+    private $end = 0;
+    private $has_end = false;
+    /**
+     * Generated from protobuf field <code>optional .google.protobuf.ExtensionRangeOptions options = 3;</code>
+     */
+    private $options = null;
+    private $has_options = false;
+
+    /**
+     * Constructor.
+     *
+     * @param array $data {
+     *     Optional. Data for populating the Message object.
+     *
+     *     @type int $start
+     *     @type int $end
+     *     @type \Google\Protobuf\Internal\ExtensionRangeOptions $options
+     * }
+     */
+    public function __construct($data = NULL) {
+        \GPBMetadata\Google\Protobuf\Internal\Descriptor::initOnce();
+        parent::__construct($data);
+    }
+
+    /**
+     * Generated from protobuf field <code>optional int32 start = 1;</code>
+     * @return int
+     */
+    public function getStart()
+    {
+        return $this->start;
+    }
+
+    /**
+     * Generated from protobuf field <code>optional int32 start = 1;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setStart($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->start = $var;
+        $this->has_start = true;
+
+        return $this;
+    }
+
+    public function hasStart()
+    {
+        return $this->has_start;
+    }
+
+    /**
+     * Generated from protobuf field <code>optional int32 end = 2;</code>
+     * @return int
+     */
+    public function getEnd()
+    {
+        return $this->end;
+    }
+
+    /**
+     * Generated from protobuf field <code>optional int32 end = 2;</code>
+     * @param int $var
+     * @return $this
+     */
+    public function setEnd($var)
+    {
+        GPBUtil::checkInt32($var);
+        $this->end = $var;
+        $this->has_end = true;
+
+        return $this;
+    }
+
+    public function hasEnd()
+    {
+        return $this->has_end;
+    }
+
+    /**
+     * Generated from protobuf field <code>optional .google.protobuf.ExtensionRangeOptions options = 3;</code>
+     * @return \Google\Protobuf\Internal\ExtensionRangeOptions
+     */
+    public function getOptions()
+    {
+        return $this->options;
+    }
+
+    /**
+     * Generated from protobuf field <code>optional .google.protobuf.ExtensionRangeOptions options = 3;</code>
+     * @param \Google\Protobuf\Internal\ExtensionRangeOptions $var
+     * @return $this
+     */
+    public function setOptions($var)
+    {
+        GPBUtil::checkMessage($var, \Google\Protobuf\Internal\ExtensionRangeOptions::class);
+        $this->options = $var;
+        $this->has_options = true;
+
+        return $this;
+    }
+
+    public function hasOptions()
+    {
+        return $this->has_options;
+    }
+
+}
+
+// Adding a class alias for backwards compatibility with the previous class name.
+class_alias(ExtensionRange::class, \Google\Protobuf\Internal\DescriptorProto_ExtensionRange::class);
+