REPL support for Symbol, undefined, NaN, and infinities

[Chris-Hibbert]

What is the Problem Being Solved?

in #2261, the REPL's stringify() was fixed to support BigInts, and @erights observed that it would fail similarly for symbols, undefined, NaN, Infinity, and -Infinity "all of which are primitive values that don't encode in JSON."

Description of the Design

Replace the special case branch with a replacer in the JSON.stringify() call that handles all these primitives.

Security Considerations

The REPL won't be able to report values containing these kinds of primitives. This results in an error, so it won't go unnoticed.

Test Plan

Added a failing test for NaN in test-repl.js