Initial Support for new stdlib shift operator
Bugfix for non-const shift amt and unit tests.
Redesign after being hit with the KISS bat.
Add docs/generic impls
Tweak generic target.
fail_db update on Linux
Fail_db update with Linux passed with LLVM 3.4
MacOS fails update
Fail_db update on Windows: 3.3 update and adding 3.4
Removing fails with g++4.4/g++4.7, as we are using clang by default now
Add shift support for generic-16 target.
Add shift support for knc targets.  This is not optimized.
Minor tweak for interface.
Merge pull request #648 from dbabokin/fail_db

fail_db update on all platforms
Make the new optimization play nicely with the other.s
Merge branch 'stdlibshift' of https://github.com/jbrodman/ispc into stdlibshift
remove condition.  Don't use gcc 4.7 for tests.
Source cleanup.
Add Performance Warning
Remove zero initialization for __vec4_i32