Merge pull request #912 from ncos/knc-backend-merge

Knc backend merge
Fail_db update
Merge pull request #913 from Vsevolod-Livinskij/fail_db_update

Fail_db update
Added cstdlib include

the atoi and other functions were not transitively included under clang/llvm3.5
Merge pull request #914 from hansbogert/master

Added cstdlib include
Fix for selfbuild to use both CC and CXX, but not only CC.
Merge pull request #917 from dbabokin/selfbuild

Fix for selfbuild to use both CC and CXX, but not only CC.
Removing -debug-ir functionality for 3.6, as it was removed from LLVM.
Merge pull request #918 from dbabokin/trunk

Removing -debug-ir functionality for 3.6, as it was removed from LLVM.
Fix for max/min_varying_uint/int64
Fix for prefetch
Some changes in max/min_varying_uint/int64
Fix for shuffle2_double
Fix for __shift_i32
Fix for __shuffle2_float
__sqrt_varying_double
Fix for unsigned cmp for int64
Fix for int64 comparison
Merge
Fix for __cast_zext(__vec16_i64, __vec16_i1)