Some examples in PartiQL spec fail to compile

[popematt]

In 6.1.4 Treatment of MISSING in SELECT VALUE, all of the examples (18-21) are not valid PartiQL. For example, SELECT VALUE {'a':v.a, 'b':v.b} FROM [{'a':1, 'b':1}, {'a':2}] has no binding for v and should actually be SELECT VALUE {'a':v.a, 'b':v.b} FROM [{'a':1, 'b':1}, {'a':2}] as v.

[alancai98]

Related to #33.

[popematt]

Oh, I didn't see that issue when I was looking for similar issues. You could close this as a duplicate if you want.