Fix rewriter issues

Allow pat_lits rewrite to map L_unit to wildcard patterns, rather than
introducing eq_unit tests as guards.

Add a fold_function and fold_funcl functions in rewriter.ml that apply
the pattern and expression algebras to top-level functions, which
means that they correctly get applied to top-level function patterns
when they are used. Currently modifying the re-writing passes to do
this introduces some bugs which needs investigated further. The
current situation is that top-level patterns and patterns elsewhere
are often treated differently because rewrite_exp doesn't (and indeed
cannot, due to how the re-writer is structured) rewrite top level
patterns.

Fix pattern completeness check for unit literals

Fix a bug in Sail->ANF transform where blocks were always annotated
with type unit incorrectly. This caused issues in pattern literal
re-writes where the guard was a block returning a boolean. A test case
for this is added as test/c/and_block.sail.

Fix a bug caused by nested polymorphic function calls and matching in
top-level patterns. Test case is test/c/tl_poly_match.sail.

Pass location info through codegen_conversion for better error
reporting

1 files changed, 2 insertions, 0 deletions

diff --git a/test/c/poly_union.sail b/test/c/poly_union.sail
index 02a80e17..ffd51a4c 100644
--- a/test/c/poly_union.sail
+++ b/test/c/poly_union.sail
@@ -1,5 +1,7 @@
 default Order dec
 
+$include <flow.sail>
+
 val print = "print_endline" : string -> unit
 
 union ast = {