Custom LLVM Statements

[L3tum]

• Decide on which statements and update this issue
• Assignment
• Function call
• Allocation
• Deallocation (And destructor calling)

This is primarily to mirror what numba did. It improves the readability of most code in LLVMGen.py and ASTVisitor.py if we don't require immediate IR generation, capsule it away nicely and also improves support variations in assignments, function calls and what not.
The ASTVisitor.py will most likely become even more of an analysis pass while LLVMGen.py will most likely lose a few methods.

[L3tum]

Actually doesn't seem like such a great idea now.