[analysis] Add a FullLattice concept and Inverted lattice (#6038)

The FullLattice concept extends the base Lattice with `getTop` and `meet`
operations. The `Inverted` lattice uses these operations to reverse the order of
an arbitrary full lattice, for example to create a lattice of integers ordered
by `>` rather than by `<`.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/analysis/lattices/bool.h b/src/analysis/lattices/bool.h
index 31094fb7d..c905d69f4 100644
--- a/src/analysis/lattices/bool.h
+++ b/src/analysis/lattices/bool.h
@@ -26,6 +26,7 @@ namespace wasm::analysis {
 struct Bool {
   using Element = bool;
   Element getBottom() const noexcept { return false; }
+  Element getTop() const noexcept { return true; }
   LatticeComparison compare(Element a, Element b) const noexcept {
     return a > b ? GREATER : a == b ? EQUAL : LESS;
   }
@@ -36,6 +37,13 @@ struct Bool {
     }
     return false;
   }
+  bool meet(Element& self, Element other) const noexcept {
+    if (self && !other) {
+      self = other;
+      return true;
+    }
+    return false;
+  }
 };
 
 #if __cplusplus >= 202002L