Regression test for https://github.com/golang/go/issues/68918:
crash due to missing type information in CompositeLit.

The corresponding go/types fix in Go 1.24 introduces a
new error message, hence the -ignore_extra_diags flag.

-- flags --
-ignore_extra_diags

-- a.go --
package a

var _ = T{{ x }} //@hiloc(x, "x", text), diag("T", re"undefined"), diag("{ ", re"missing type")

//@highlight(x, x)
