PHP array constructors for protobuf messages (#4530)

* PHP array constructors for protobuf messages

* removes Descriptor from error message

* allows mergeFrom to accept an array

* only use initWithDescriptor if instanceof MapEntry

* adds doc comments

* removes ability for constructors to take arrays for submessages

* Revert "allows mergeFrom to accept an array"

This reverts commit b7b72182d561634af12c5c5c56a7cda3b33241f9.

* makes mergeFromArray protected and fixes mergeFrom whitespace

* Separates merging from JSON and merging from PHP array

* removes well-known types and json keys from array construction

* Addresses PR review comments

* cleans up tests

* fixes exception messages

1 files changed, 22 insertions, 2 deletions

diff --git a/php/src/Google/Protobuf/Internal/GeneratedCodeInfo_Annotation.php b/php/src/Google/Protobuf/Internal/GeneratedCodeInfo_Annotation.php
index 22ac2337..75182007 100644
--- a/php/src/Google/Protobuf/Internal/GeneratedCodeInfo_Annotation.php
+++ b/php/src/Google/Protobuf/Internal/GeneratedCodeInfo_Annotation.php
@@ -48,9 +48,29 @@ class GeneratedCodeInfo_Annotation extends \Google\Protobuf\Internal\Message
     private $end = 0;
     private $has_end = false;
 
-    public function __construct() {
+    /**
+     * Constructor.
+     *
+     * @param array $data {
+     *     Optional. Data for populating the Message object.
+     *
+     *     @type int[]|\Google\Protobuf\Internal\RepeatedField $path
+     *           Identifies the element in the original source .proto file. This field
+     *           is formatted the same as SourceCodeInfo.Location.path.
+     *     @type string $source_file
+     *           Identifies the filesystem path to the original source .proto.
+     *     @type int $begin
+     *           Identifies the starting offset in bytes in the generated code
+     *           that relates to the identified object.
+     *     @type int $end
+     *           Identifies the ending offset in bytes in the generated code that
+     *           relates to the identified offset. The end offset should be one past
+     *           the last relevant byte (so the length of the text = end - begin).
+     * }
+     */
+    public function __construct($data = NULL) {
         \GPBMetadata\Google\Protobuf\Internal\Descriptor::initOnce();
-        parent::__construct();
+        parent::__construct($data);
     }
 
     /**