Fix bug: handle missing symbol.parent for non-accessible symbol (#21834)

Author: Andy

src/services/completions.ts

@@ -712,7 +712,7 @@ namespace ts.Completions {
     function getFirstSymbolInChain(symbol: Symbol, enclosingDeclaration: Node, checker: TypeChecker): Symbol | undefined {
         const chain = checker.getAccessibleSymbolChain(symbol, enclosingDeclaration, /*meaning*/ SymbolFlags.All, /*useOnlyExternalAliasing*/ false);
         if (chain) return first(chain);
-        return isModuleSymbol(symbol.parent) ? symbol : symbol.parent && getFirstSymbolInChain(symbol.parent, enclosingDeclaration, checker);
+        return symbol.parent && (isModuleSymbol(symbol.parent) ? symbol : getFirstSymbolInChain(symbol.parent, enclosingDeclaration, checker));
     }
 
     function isModuleSymbol(symbol: Symbol): boolean {

tests/cases/fourslash/completionsRecommended_nonAccessibleSymbol.ts

@@ -0,0 +1,10 @@
+/// <reference path="fourslash.ts" />
+
+////function f() {
+////    class C {}
+////    return (c: C) => void;
+////}
+////f()(new /**/);
+
+goTo.marker("");
+verify.not.completionListContains("C"); // Not accessible