Replace 'isSourceFileJavaScript(getSourceFileOfNode())' with 'NodeFlags.JavaScriptFile' (#17835)

Author: Andy

src/compiler/checker.ts

@@ -19655,7 +19655,7 @@ namespace ts {
                 // checkFunctionOrConstructorSymbol wouldn't be called if we didnt ignore javascript function.
                 const firstDeclaration = find(localSymbol.declarations,
                     // Get first non javascript function declaration
-                    declaration => declaration.kind === node.kind && !isSourceFileJavaScript(getSourceFileOfNode(declaration)));
+                    declaration => declaration.kind === node.kind && !(declaration.flags & NodeFlags.JavaScriptFile));
 
                 // Only type check the symbol once
                 if (node === firstDeclaration) {