Sema: Add hack until we can request-ify computeCaptures()

typeCheckDecl() is not going to get called on a synthesized
accessor if its in local context. Previously, accessors in
local context were only created by the parser, but that
code path is going away.

Until capture computation is request-ified, force it to
happen for accessors of local properties.

Author: slavapestov

lib/Sema/TypeCheckDecl.cpp

@@ -2335,6 +2335,16 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
 
     triggerAccessorSynthesis(TC, VD);
 
+    // FIXME: Temporary hack until capture computation has been request-ified.
+    if (VD->getDeclContext()->isLocalContext()) {
+      VD->visitExpectedOpaqueAccessors([&](AccessorKind kind) {
+        auto accessor = VD->getAccessor(kind);
+        if (!accessor) return;
+
+        TC.definedFunctions.push_back(accessor);
+      });
+    }
+
     // Under the Swift 3 inference rules, if we have @IBInspectable or
     // @GKInspectable but did not infer @objc, warn that the attribute is
     if (!VD->isObjC() && TC.Context.LangOpts.EnableSwift3ObjCInference) {