CodeGen: Strip qualifiers from qualified array types in catches

While we ran getUnqualifiedType over the catch type,
it isn't enough for array types.  Use getUnqualifiedArrayType instead.

This fixes PR21252.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219582 91177308-0d34-0410-b5e6-96231b3b80d8