* Reland "Fix: check if param is assignable when parsing arrow return type annotation" This reverts commit 91a7a64b4b0c30ab1fdfbb12f77522afa2285ec4. * Mark `RestElement` as assignable
* Reland "Fix: check if param is assignable when parsing arrow return type annotation" This reverts commit 91a7a64b4b0c30ab1fdfbb12f77522afa2285ec4. * Mark `RestElement` as assignable