Merge branch 'master' into specialize_branched_loops
Merge branch 'specialize_branched_loops' of https://github.com/halide/Halide into specialize_branched_loops
Fixed a serious bug that was caused by allocate nodes with conditions. The solution is currently to exclude these cases from branching. More precisely I exclude from branching the produce/update stages of a pipeline if they are guarded by an if stmt with a condition equivalent to the corresponding allocate's condition. The if guard is left alone and will appear in all branches.
Merge branch 'specialize_branched_loops' of https://github.com/halide/Halide into specialize_branched_loops