Pass DynamicLookupInfo through VisibleDeclConsumers NFC

This commit adds a new type DynamicLookupInfo that provides information
about how a dynamic member lookup found a particular Decl. This is
needed to correctly handle KeyPath dynamic member lookups, but for now
just plumb it through everywhere.

lib/FrontendTool/ReferenceDependencies.cpp

@@ -437,7 +437,8 @@ void ProvidesEmitter::emitDynamicLookupMembers() const {
       SmallVector<DeclBaseName, 16> names;
 
     public:
-      void foundDecl(ValueDecl *VD, DeclVisibilityKind Reason) override {
+      void foundDecl(ValueDecl *VD, DeclVisibilityKind Reason,
+                     DynamicLookupInfo) override {
         names.push_back(VD->getBaseName());
       }
       ArrayRef<DeclBaseName> getNames() {