The issue is only going to be properly fixed when we rewrite `csimp`
in Lean. The `csimp` performs transformations that do not preserve
typability, but it also uses the kernel `infer_type` which assumes the
input is type correct. In the new `csimp`, we must have a different
`infer_type` which returns an `Any` type in this kind of situation.
The workaround in this commit simply disables optimizations when
`infer_type` fails. It does not fix all occurrences of this problem,
but the two places that issue #1030 triggered.
closes#1030
