asserts and declare in classes are not colored as a keyword

[AlCalzone]

TS and JS Grammar Extension version: The one included in VSCode 1.41.1

I was asked to split microsoft/TypeScript#35187 and open it here.

Code

function foo(x: any): asserts x is "a" {

}

class Foo {
    declare baz: any;
}

Expected behavior:
asserts is colored like the other keywords.
declare is colored like the other keywords.

Actual behavior:
They are not. (Except declare, which is colored in the playground, but not VSCode).

TS Playground: http://www.typescriptlang.org/play/?ts=3.8.0-dev.20191116#code/GYVwdgxgLglg9mABMOcAUAPAXIghmATwEodcBnMgUwCcozENEZ6AiXFxAbwChE-EA9AMQBaMeImSAeojBw8IKHAhwAtgAcANpSiVkcaojYUadFtwC+3bhE3l6AMVRde-ACaVbuanoBGuAC9SQgBuVz4hUTFZeVxFZTUtHT0UQxYPLx9zfkFhXwJEKAALPQB3XAIAGkRSkp8memLcKEQVVVVKMBaEQpLEahgAcyKWshgPAH5LIA