Dear all,

there are a couple of NULL pointer dereferences leading to improper
error recovery when trying to handle Gerhard's testcases involving
SELECT TYPE and invalid uses of CLASS variables.

The fixes look pretty obvious to me, but I'm submitting here to
check if there is more that should be done here.

(I was surprised to see that there are several different places
involved by rather simple variations in the basic test case.)

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald