AST: Fix calculation of recursive properties for SILBoxType

We need to propagate some bits from the field types, at least the
'has dynamic self' bit, for some SIL verifier assertions to not fire.

Author: slavapestov

lib/AST/Type.cpp

@@ -4056,9 +4056,15 @@ void SILBoxType::Profile(llvm::FoldingSetNodeID &id, SILLayout *Layout,
   Substitutions.profile(id);
 }
 
-static RecursiveTypeProperties getRecursivePropertiesOfMap(
-                                                      SubstitutionMap subMap) {
+static RecursiveTypeProperties getBoxRecursiveProperties(
+    SILLayout *Layout, SubstitutionMap subMap) {
   RecursiveTypeProperties props;
+  for (auto &field : Layout->getFields()) {
+    auto fieldProps = field.getLoweredType()->getRecursiveProperties();
+    fieldProps.removeHasTypeParameter();
+    fieldProps.removeHasDependentMember();
+    props |= fieldProps;
+  }
   for (auto replacementType : subMap.getReplacementTypes()) {
     if (replacementType) props |= replacementType->getRecursiveProperties();
   }
@@ -4067,7 +4073,8 @@ static RecursiveTypeProperties getRecursivePropertiesOfMap(
 
 SILBoxType::SILBoxType(ASTContext &C,
                        SILLayout *Layout, SubstitutionMap Substitutions)
-  : TypeBase(TypeKind::SILBox, &C, getRecursivePropertiesOfMap(Substitutions)),
+  : TypeBase(TypeKind::SILBox, &C,
+             getBoxRecursiveProperties(Layout, Substitutions)),
     Layout(Layout), Substitutions(Substitutions) {
   assert(Substitutions.isCanonical());
 }

test/SILGen/dynamic_self.swift

@@ -224,6 +224,21 @@ class Z {
     return self.init()
   }
 
+  static func testStaticMethodMutableDynamicSelfCaptures() -> Self {
+    let fn0 = { _ = self; _ = { _ = self } }
+    fn0()
+
+    var x = self
+    let fn1 = { _ = x }
+    fn1()
+
+    var xx = (self, self)
+    let fn2 = { _ = xx }
+    fn2()
+
+    return self.init()
+  }
+
   // Make sure the actual self value has the same lowered type as the
   // substituted result of a generic function call
   func testDynamicSelfSubstitution(_ b: Bool) -> Self {