Add @simd support.
This is a collective commit that supercedes the earlier commits for @simd.
Update to work with LLVM 3.4 too (in addition to LLVM 3.3)
Generialize @simd loops to one dimensional ranges instead of requiring a:b syntax.
Fix names of some TBAA nodes.
Fix spelling in comment.
Add missing semicolon for MCJIT variant of codegen.cpp.
Remove tbaa_decorate from load/stores of local vars described by jl_arrayvar_t.
Treat loading of string pointer as tbaa_const.
Improve hoisting of size intrinsic.
Document @simd as experimental.