Strange parser behavior: No completions before property whose value is ``

TypeScript Version: 3.2.0-dev.20181023

Code

/// <reference path='fourslash.ts' />

////f({
////    a/**/
////    xyz: ``,
////});
////declare function f(options: { abc?: number, xyz?: string }): void;

verify.completions({
    marker: "",
    exact: ["abc"],
});

Expected behavior:

Test passes.

Actual behavior:

No completions.
The test passes if I change `` to "".