Unreviewed attempt to fix 32-bit builds.

Use long long rather than GC3Dintptr.

* html/canvas/ANGLEInstancedArrays.cpp:
(WebCore::ANGLEInstancedArrays::drawElementsInstancedANGLE):
* html/canvas/ANGLEInstancedArrays.h:
* html/canvas/WebGLRenderingContext.cpp:
(WebCore::WebGLRenderingContext::drawElementsInstanced):
* html/canvas/WebGLRenderingContext.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162567 268f45cc-cd09-0410-ab3c-d52691b4dbfc