The ARB_gpu_shader_fp64 coverage was the last remaining extension for Intel Haswell to see OpenGL 4.0 compliance. That's finally done and now the remaining patches were pushed today for turning on OpenGL 4.0. As long as you're on a sufficiently new kernel, OpenGL 4.0 will be turned on for Haswell hardware next time you pull from Mesa master.
The Ivy Bridge FP64 support still appears to be a ways out. Blocking Haswell from OpenGL 4.1 and later extensions is GL_ARB_vertex_attrib_64bit support that still needs to land. Broadwell and newer hardware meanwhile has been on OpenGL 4.5 since Mesa 13.0.