Added new has_bits.h file to cmake/extract_includes.bat.in (#2152)

This is necessary so that the CMake build knows to include this header
file in the installation include/ directory.

cmake/extract_includes.bat.in

@@ -49,6 +49,7 @@ copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\generated_enum_reflect
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\generated_enum_util.h include\google\protobuf\generated_enum_util.h
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\generated_message_reflection.h include\google\protobuf\generated_message_reflection.h
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\generated_message_util.h include\google\protobuf\generated_message_util.h
+copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\has_bits.h include\google\protobuf\has_bits.h
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\io\coded_stream.h include\google\protobuf\io\coded_stream.h
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\io\gzip_stream.h include\google\protobuf\io\gzip_stream.h
 copy ${PROTOBUF_SOURCE_WIN32_PATH}\..\src\google\protobuf\io\printer.h include\google\protobuf\io\printer.h