Handle E_FunctionCall(E1_StructTypeReference) when determining whether a function is recursive
Rewrite E_FunctionCall(E1_StructTypeReference) into E1_New
Add a newline at end of gc.cc
Traverse world->associations when collecting functions. This enables optimization passes to optimize function bodies hidden behind the associations.
Fix C++ code behind #if directives
Value propagation: omit the abstract part from the product of evaluating S_Abstract