Efficient C implementation of expanded

1. Proposal 1
2. Proposal 2
3. Proposal 3
4. Proposal 4

From those 4 proposals, we decided to go for implementation number 3 for the following reasons:

• easy to manage incremental recompilation
• ease of C stack management and conversion from locals to attributes and vice versa
• Easy to optimize expanded without references
• Already a major improvement over previous implementation