Native bindings to the AMD_blend_minmax_factor extension.

The EXT_blend_minmax extension extended the GL's blending functionality to allow the blending equation to be specified by the application. That extension introduced the MIN_EXT and MAX_EXT blend equations, which caused the result of the blend equation to become the minimum or maximum of the source color and destination color, respectively.

The MIN_EXT and MAX_EXT blend equations, however, do not include the source or destination blend factors in the arguments to the min and max functions. This extension provides two new blend equations that produce the minimum or maximum of the products of the source color and source factor, and the destination color and destination factor.