Empty type inferred by Object.entries

TypeScript Version: 2.7.1

Search Terms: Object entries empty TS2365

Code

let o: any = {x: 5};

let p = Object.entries(o).map(([k, v]) => v + 1);

Compile command: tsc --lib es2017,es2017.object a.ts

Expected behavior:
This should compile without any error, assuming v: any.
This was the case for Typescript 2.6.2 at least.

Actual behavior:
(3,43): error TS2365: Operator '+' cannot be applied to types '{}' and '1'.

Following codes compile without errors:

let o: object = {x: 5};

let p = Object.entries(o).map(([k, v]) => v + 1);

let o: any = {x: 5};

let p = Object.entries(o).map(([k, v]: [any, any]) => v + 1);

Reproduce the report in a.ts with TypeScript 2.7.1 using tsc --lib es2017,es2017.object a.ts, then compare the Object.entries inference with the 2.6.2 behavior described here. Start by tracing the typings and inferred tuple element types for the shown map callback. Done when the original example compiles as expected without breaking the explicitly annotated alternatives.