That codepath is taken in qml when an Image specify with and hight and
is not smooth, and the image contains alpha contents
The changes in qdrawingprimitive_sse2_p.h just put some code from the
BLEND_SOURCE_OVER_ARGB32_SSE2 macro into a sub macro to allow its reuse
The code that is not SSE2 in qt_scale_image_argb32_on_argb32_sse2 comes
from the qt_scale_image_argb32_on_argb32 in qblendfunctions.cpp
Change-Id: I071a040af4514fb21777dead9f7c5baf16071d59
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>