ASTC is supported by OpenGL ES 3.1 and above.
To build this patch with ASTC support, a GLES 31 context must be specified.

To build for desktop with configure, the gles version must be set to 31.
Here is an example configure line:
CXXFLAGS="-g -O0 -Wno-unused-local-typedefs" CXX="ccache g++" ./configure --prefix=$DESKTOP_PREFIX --enable-debug=yes --enable-profile=UBUNTU --enable-gles=31

With GBS, add the following to your gbs build line:
--define "%target_gles_version 31"

Change-Id: I4f54f894dd4b8998f16aa98d3d0a06606f0eb7a2