[CS] Walk ExprPattern conjunction elements when finding type variables

Apply the same logic that we apply to other
conjunction elements, to make sure that e.g
property wrapper projected values work correctly.

rdar://110649179

Author: hamishknight

lib/Sema/CSSyntacticElement.cpp

@@ -2625,8 +2625,10 @@ void ConjunctionElement::findReferencedVariables(
   }
 
   if (element.is<Decl *>() || element.is<StmtConditionElement *>() ||
-      element.is<Expr *>() || element.isStmt(StmtKind::Return))
+      element.is<Expr *>() || element.isPattern(PatternKind::Expr) ||
+      element.isStmt(StmtKind::Return)) {
     element.walk(refFinder);
+  }
 }
 
 Type constraints::isPlaceholderVar(PatternBindingDecl *PB) {

test/Constraints/issue-66561.swift

@@ -0,0 +1,36 @@
+// RUN: %target-typecheck-verify-swift
+
+// https://github.com/apple/swift/issues/66561
+
+@propertyWrapper
+struct WrapperValue<Value> {
+  var value: Value
+  init(wrappedValue: Value) {
+    self.value = wrappedValue
+  }
+
+  var projectedValue: Self {
+    return self
+  }
+
+  var wrappedValue: Value {
+    get {
+      self.value
+    }
+    set {
+      self.value = newValue
+    }
+  }
+}
+
+func test() {
+  let _ = {
+    @WrapperValue var value: Bool = false
+    switch value {
+    case $value.wrappedValue:
+      break
+    default:
+      break
+    }
+  }
+}