Add new file option php_namespace. (#3162)

* Add new file option php_namespace.

Use this option to change the namespace of php generated classes.
Default is empty. When this option is empty, the package name will be
used for determining the namespace.

* Uncomment commented tests

* Revert gdb test change

* Update csharp descriptor.

* Add test for empty php_namespace.

1 files changed, 10 insertions, 0 deletions

diff --git a/php/src/Google/Protobuf/Internal/SourceCodeInfo_Location.php b/php/src/Google/Protobuf/Internal/SourceCodeInfo_Location.php
index 5a02b26c..cf23e38b 100644
--- a/php/src/Google/Protobuf/Internal/SourceCodeInfo_Location.php
+++ b/php/src/Google/Protobuf/Internal/SourceCodeInfo_Location.php
@@ -182,6 +182,8 @@ class SourceCodeInfo_Location extends \Google\Protobuf\Internal\Message
         $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
         $this->path = $arr;
         $this->has_path = true;
+
+        return $this;
     }
 
     public function hasPath()
@@ -221,6 +223,8 @@ class SourceCodeInfo_Location extends \Google\Protobuf\Internal\Message
         $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::INT32);
         $this->span = $arr;
         $this->has_span = true;
+
+        return $this;
     }
 
     public function hasSpan()
@@ -322,6 +326,8 @@ class SourceCodeInfo_Location extends \Google\Protobuf\Internal\Message
         GPBUtil::checkString($var, True);
         $this->leading_comments = $var;
         $this->has_leading_comments = true;
+
+        return $this;
     }
 
     public function hasLeadingComments()
@@ -345,6 +351,8 @@ class SourceCodeInfo_Location extends \Google\Protobuf\Internal\Message
         GPBUtil::checkString($var, True);
         $this->trailing_comments = $var;
         $this->has_trailing_comments = true;
+
+        return $this;
     }
 
     public function hasTrailingComments()
@@ -368,6 +376,8 @@ class SourceCodeInfo_Location extends \Google\Protobuf\Internal\Message
         $arr = GPBUtil::checkRepeatedField($var, \Google\Protobuf\Internal\GPBType::STRING);
         $this->leading_detached_comments = $arr;
         $this->has_leading_detached_comments = true;
+
+        return $this;
     }
 
     public function hasLeadingDetachedComments()