Book samples: fix test SimpleBufferSubBuffer
Book samples: patch ImageFilter2D with constant qualifier for global array
Enable book samples also with the ICD build.
Merge branch 'fix_booksamples' of https://github.com/clementleger/pocl
Binary test is broken with LLVM API mode.
Fix HelloBinaryWorld of the book samples.
Merge branch 'master' of https://github.com/pocl/pocl