Deal better with array delcarations in the cross compiler. Closes #17.
Implement SSA minimization
Allow the constant folder to avoid ever substituting certain variables.
Use sets instead of vectors for OpInfo
Pass around a reference to the op list to the various IR functions, instead of transferring ownership.
A *totally* wrong workaround to the StructTy failures in ccross.
Add RUST_FLAGS variable to Makefile
Update collections to std::collections for lastest rust