toward vectorization: intrinsic selection (x86)

src/pystencils/backend/arrays.py

src/pystencils/backend/ast/collectors.py

src/pystencils/backend/ast/kernelfunction.py

src/pystencils/backend/ast/nodes.py

src/pystencils/backend/emission.py

src/pystencils/backend/functions.py

src/pystencils/backend/jit/legacy_cpu.py

src/pystencils/backend/kernelcreation/freeze.py

src/pystencils/backend/kernelcreation/typification.py

src/pystencils/backend/platforms/__init__.py

src/pystencils/backend/platforms/platform.py

src/pystencils/backend/platforms/x86.py

src/pystencils/backend/transformations/__init__.py

src/pystencils/backend/transformations/vector_intrinsics.py

src/pystencils/backend/types/basic_types.py