Playground: tsconfig.json editor shows 'target: ES3' when URL uses target=99

[mjpieters]

Opening the 'TS Config' option on any playground URL with target=99 shows Target: ES3 instead.

Repro:

Compare these two URLs:

• https://www.typescriptlang.org/play?target=99&jsx=0#code/MYewdgzgLgBAZiEBeA5AIwIYCcVA
• https://www.typescriptlang.org/play?target=7&jsx=0#code/MYewdgzgLgBAZiEBeA5AIwIYCcVA

and open the TS Config menu on either. The first will show ES3 as the selected target while the second correctly shows ES2020.

Expected behavior:

The TS Config Target dropdown should reflect the selected target correctly, for all possible targets.

Actual behavior:

Only when using target=99 does the dropdown reflect the wrong choice. For all other possible target values, the dropdown shows the correct value.

Note that the compiler appears to be correctly configured, e.g. a playground link demonstrating a TypeScript bug with involving a ESNext-only feature only highlights 'compact' as a problem (the [subject of my bug report that led to this one) while any target option other than ESNext / Latest would produce more errors.

[mjpieters]

Duplicate of #1136. Mea Culpa!