VSCode Syntax highlighting broken when using TypeScript multiline generics in ES6 object function shorthand syntax

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.62.3
• OS Version: macOS 11.6.1

Steps to Reproduce:

1. Create a typescript file with the following code:

const obj = {
	fn<
		K extends string
	>(_: K) {
		const a = 'a';

		function _f() {
			const b = 'b';
			return b;
		}

		return a;
	},
};

const obj2 = {
	fn<K extends string>(_: K) {
		const a = 'a';

		function _f() {
			const b = 'b';
			return b;
		}

		return a;
	},
};

2. Notice how the syntax highlighting is broken in the first object declaration:

Reproduce the issue in VS Code with the TypeScript snippet, comparing the multiline generic with the single-line form. Then inspect the repository's TypeScript TextMate grammar files to find the rule handling object function shorthand and multiline generics. Done means both forms receive correct syntax highlighting without affecting the surrounding function body.