Re-improve recovery when the condition of a switch statement does not

Re-improve recovery when the condition of a switch statement does not
have integral or enumeration type, so that we still check the contents
of the switch body. My previous patch made this worse; now we're back
to where we were previously.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107223 91177308-0d34-0410-b5e6-96231b3b80d8