Don't generate code for no-op ivars initializers
Fixed #138: pointerof(var) marks var as being read and it has an alloca in the codegen
Continued closured. Create nested contexts for blocks with a reference to the parent closure context.
Remamed Block#before_vars to Block#vars
Codegen: collect closured vars in a separate method
Put some names to LLVM instructions to make it easier to debug closures
Parser: use different names for implicit block arguments
Added a spec and some comments for explaining why we need to call undef_vars before a call with a block
Fixed some issues with closures and blocks
More correct way to gather closured vars in codegen
Correctly set/use parent closure context
Make closured work in blocks that don't closure vars but an outer context has closured vars
More closure cases with nested contexts