2013-11-24  Sharath Kamath  <s.kamath@samsung.com>

        In WebCLProgram::Build, sequence of device is optional.
        Issue #347

        Reviewed by Antonio.

        As per the specification, device list is optional.
        In absense of device list we build using the devices associated with
        context the program is created from.

        Conformance test:
        conformance/basicoperations/cl_program_build.html

        * Modules/webcl/WebCLProgram.idl:
        * bindings/js/JSWebCLProgramCustom.cpp:
        (WebCore::JSWebCLProgram::build):