TComp/passesInstrument.md

1. OK: uniquify deals with the shadowing of variables by renaming every variable to a unique name.
2. OK remove_complex_operands ensures that each subexpression of a primitive operation or function call is a variable or integer, that is, an atomic expression. We refer to nonatomic expressions as complex. This pass introduces temporary variables to hold the results of complex subexpressions.
3. OK explicate_control makes the execution order of the program explicit. It converts the abstract syntax tree representation into a graph in which each node is a labeled sequence of statements and the edges are goto statements.
4. select_instructions handles the difference between LVar operations and x86 instructions. This pass converts each LVar operation to a short sequence of instructions that accomplishes the same task. assign_homes