[red-knot] Use ternary decision diagrams (TDDs) for visibility constraints

crates/red_knot_python_semantic/resources/mdtest/statically_known_branches.md

@@ -1489,37 +1489,6 @@ if True:
 from module import symbol
 ```
 
-## Known limitations
-
-We currently have a limitation in the complexity (depth) of the visibility constraints that are
-supported. This is to avoid pathological cases that would require us to recurse deeply.
-
-```py
-x = 1
-
-False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or (x := 2)  # fmt: skip
-
-# This still works fine:
-reveal_type(x)  # revealed: Literal[2]
-
-y = 1
-
-False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or False or \
-    False or False or False or (y := 2)  # fmt: skip
-
-# TODO: This should ideally be `Literal[2]` as well:
-reveal_type(y)  # revealed: Literal[1, 2]
-```
-
 ## Unsupported features
 
 We do not support full unreachable code analysis yet. We also raise diagnostics from

crates/red_knot_python_semantic/src/semantic_index/constraint.rs

@@ -5,20 +5,20 @@ use crate::db::Db;
 use crate::semantic_index::expression::Expression;
 use crate::semantic_index::symbol::{FileScopeId, ScopeId};
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub(crate) struct Constraint<'db> {
     pub(crate) node: ConstraintNode<'db>,
     pub(crate) is_positive: bool,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub(crate) enum ConstraintNode<'db> {
     Expression(Expression<'db>),
     Pattern(PatternConstraint<'db>),
 }
 
 /// Pattern kinds for which we support type narrowing and/or static visibility analysis.
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, Hash, PartialEq)]
 pub(crate) enum PatternConstraintKind<'db> {
     Singleton(Singleton, Option<Expression<'db>>),
     Value(Expression<'db>, Option<Expression<'db>>),