AST: Find local property wrappers in ASTScope::lookupLocalDecls()

Two fixes here:

- The ASTScopeDeclConsumerForLocalLookup needs to visit auxiliary variables
- preCheckExpression() should call ASTScope::lookupLocalDecls() even when
  parser lookup is enabled, since otherwise we won't be able to find
  auxiliary decls in the current DeclContext.

Author: slavapestov

lib/AST/UnqualifiedLookup.cpp

@@ -784,10 +784,17 @@ class ASTScopeDeclConsumerForLocalLookup
   bool consume(ArrayRef<ValueDecl *> values,
                NullablePtr<DeclContext> baseDC) override {
     for (auto *value: values) {
-      if (!value->getName().matchesRef(name))
-        continue;
+      if (auto *varDecl = dyn_cast<VarDecl>(value)) {
+        // Check if the name matches any auxiliary decls not in the AST
+        varDecl->visitAuxiliaryDecls([&](VarDecl *auxiliaryVar) {
+          if (name.isSimpleName(auxiliaryVar->getName())) {
+            results.push_back(auxiliaryVar);
+          }
+        });
+      }
 
-      results.push_back(value);
+      if (value->getName().matchesRef(name))
+        results.push_back(value);
     }
 
     return (!stopAfterInnermostBraceStmt && !results.empty());

lib/Sema/PreCheckExpr.cpp

@@ -357,17 +357,16 @@ Expr *TypeChecker::resolveDeclRefExpr(UnresolvedDeclRefExpr *UDRE,
   SmallVector<ValueDecl*, 4> ResultValues;
 
   auto &Context = DC->getASTContext();
-  if (Context.LangOpts.DisableParserLookup) {
-    // First, look for a local binding in scope.
-    if (Loc.isValid() && !Name.isOperator()) {
-      SmallVector<ValueDecl *, 2> localDecls;
-      ASTScope::lookupLocalDecls(DC->getParentSourceFile(),
-                                 Name.getFullName(), Loc,
-                                 /*stopAfterInnermostBraceStmt=*/false,
-                                 ResultValues);
-      for (auto *localDecl : ResultValues) {
-        Lookup.add(LookupResultEntry(localDecl), /*isOuter=*/false);
-      }
+
+  // First, look for a local binding in scope.
+  if (Loc.isValid() && !Name.isOperator()) {
+    SmallVector<ValueDecl *, 2> localDecls;
+    ASTScope::lookupLocalDecls(DC->getParentSourceFile(),
+                               Name.getFullName(), Loc,
+                               /*stopAfterInnermostBraceStmt=*/false,
+                               ResultValues);
+    for (auto *localDecl : ResultValues) {
+      Lookup.add(LookupResultEntry(localDecl), /*isOuter=*/false);
     }
   }