Cannot parse "show create table a.b"

[andremarianiello]

Queries like

select * from `a.b`

parse, but

show create table `a.b`

does not. It fails with

expecting "`" but got "." instead

I think

go-mysql-server/sql/parse/util.go

Lines 236 to 240 in 1d000c3

	steps = parseFuncs{
	expectQuote,
	readIdent(ident),
	expectQuote,
	}

is to blame because readIdent tries to parse a valid identifier, but since we are in backticks we should be accepting almost anything here instead.

[andremarianiello]

I have a branch with changes that appear to fix this, so I will make a PR for that, but if you don't like the solution I am totally fine with using someone else's fix.