A holey array converted to a checked-dynamic value keeps its holes (the
conversion records them in the array's presence map), but the runtime
inspector printed every element: `const u: unknown = a` for
`a[2] = 1` printed `[ undefined, undefined, 1 ]`, where Node prints
`[ <2 empty items>, 1 ]`, and `new Array(3)` through `unknown` printed
`[ undefined, undefined, undefined ]`.
The inspector now prints each run of holes as one `<n empty items>`
entry that counts toward the 100-entry limit, as Node's
formatSpecialArray does and as the typed array inspector already does.
Chris Tate
60f5c852e0