Convert test to CHECK-LABEL

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213161 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen: don't form illegail EXTLOAD operations.

It turns out that in most cases (the main exception being i1-related
types) once these operations are formed we cannot separate them and
the targets end up having to deal with them whether they want to or
not.

This is not a good situation, and a more reasonable default can be
formed by ackowledging this and having targets leave them as Legal.
Only x86 seems to be affected (other targets don't even try marking
the operation Expand).

Mostly there's no visible change here yet, but it will be useful to
have truly expanded EXTLOADS for MVT::f16 softening support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213162 91177308-0d34-0410-b5e6-96231b3b80d8