[IR] Print the label operands of a catchpad like an invoke

[IR] Print the label operands of a catchpad like an invoke

The rest of the EH pads are fine, since they have at most one label and
take fewer operands for the personality.

Old catchpad vs. new:
  %5 = catchpad [i8* bitcast (i32 ()* @"\01?filt$0@0@main@@" to i8*)] to label %__except.ret.10 unwind label %catchendblock.9
-----
  %5 = catchpad [i8* bitcast (i32 ()* @"\01?filt$0@0@main@@" to i8*)]
          to label %__except.ret.10 unwind label %catchendblock.9

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247433 91177308-0d34-0410-b5e6-96231b3b80d8