knc.h: added [] overloads to type defenitions
Merge branch 'master' of https://github.com/ncos/ispc into knc-backend-merge
changed the names of 'reduce' functions (ixx -> intxx) to match the names generated by code generator
Commented out the faulty functions. Our code generator does not provide the necessary alligning to use them.
Merge pull request #885 from ncos/knc-backend-merge

Further improvements in knc.h