This test checks that diagnostics ranges computed with the TypeErrorEndPos
heuristic span at least a full token.

-- go.mod --
module example.com

go 1.21

-- main.go --
package main

import "example.com/foo-bar" //@ diag(re`"[^"]*"`, re`not used`, exact=true)

func f(int) {}

func main() {
	var x int
	_ = x + 1.e+0i //@ diag("1.e+0i", re`truncated`, exact=true)
}

-- foo-bar/baz.go --
package foo
