Test JSON bool, null literal shorthand names

[theory]

Section 2.5.1.1 defines shorthand names with this grammar:

member-name-shorthand = name-first *name-char
name-first          = ALPHA /
                      "_"   /
                      %x80-D7FF /
                         ; skip surrogate code points
                      %xE000-10FFFF
name-char           = name-first / DIGIT

This allows shorthand names that correspond to the JSON literals true, false, and null.

So add tests for this pattern.

[taimoorzaeem]

Hi @theory, these tests look good to merge.

I was just wondering, what's the use case for covering these cases? I can't think of any case where an implementation would work fine with $.name but not with $.true. 🤔

[theory]

Here's one: mine. I had overlooked including bools and null in a switch statement. :-)

[f3ath]

LG and passes for me. @gregsdennis any objections?