Fix declaration emit for JS default re-exports that resolve to modules through synthesized default exports (#56340)

src/compiler/checker.ts

@@ -9744,6 +9744,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                         // does not use localName because the symbol name in this case refers to the name in the exports table,
                         // which we must exactly preserve
                         const specifier = (node.parent.parent as ExportDeclaration).moduleSpecifier;
+                        if (specifier && (node as ExportSpecifier).propertyName?.escapedText === InternalSymbolName.Default) {
+                            verbatimTargetName = InternalSymbolName.Default;
+                        }
                         // targetName is only used when the target is local, as otherwise the target is an alias that points at
                         // another file
                         serializeExportSpecifier(