* Function names should start with %
* Create FunctionName from string
* Implement displaying of FunctionName as %nnnn with fallback to #xxxx
* Run rustfmt and fix FunctionName::with_string in parser
* Implement FunctionName::new as a generic function
* Binary function names should start with #
* Implement NameRepr for function name
* Fix examples in docs to reflect that function names start with %
* Rebase and fix filecheck tests
The DominatorTree has existing DomNodes per EBB that can be used in lieu
of expensive HastSets for the depth-first traversal of the CFG.
Make the computed and cached post-order available for other passes
through the `cfg_postorder()` method which returns a slice.
The post-order algorithm is essentially the same as the one in
ControlFlowGraph::postorder_ebbs(), except it will never push a
successor node that has already been visited once. This is more
efficient, but it generates a different post-order.
Change the cfg_traversal tests to check this new algorithm.
Move the flow graph computation into a compute method which can be
called with multiple functions.
This allows us to reuse the ControlFlowGraph memory and keep an instance
in the Context.
