[CodeCompletion] Don't suggest initializers on 'AnyObject'

'AnyObject' cannot be instantiated, we shouldn't be providing any
initializers on 'AnyObject' type. 'AnyObject(<HERE>' and global
completions with initializers (i.e. `addinitstotoplevel`) showed all
initializers from objc classes.

Note that, 'lookupVisibleMemberDecls()' on 'AnyObject' (i.e.
'AnyObject.<HERE>') doesn't return initializers even before this change.
But 'QualifiedLookup' did.

rdar://93059166

lib/IDE/ExprContextAnalysis.cpp

@@ -365,6 +365,10 @@ static void collectPossibleCalleesByQualifiedLookup(
   if (!baseInstanceTy->mayHaveMembers())
     return;
 
+  // 'AnyObject' is not initializable.
+  if (baseInstanceTy->isAnyObject() && name == DeclNameRef::createConstructor())
+    return;
+
   // Make sure we've resolved implicit members.
   namelookup::installSemanticMembersIfNeeded(baseInstanceTy, name);