A landing pad could have more than one predecessor. In that case, we want that

A landing pad could have more than one predecessor. In that case, we want that
predecessor to remove the jump to it as well. Delay clearing the 'landing pad'
flag until after the jumps have been removed. (There is an implicit assumption
in several modules that an MBB which jumps to a landing pad has only two
successors.)
<rdar://problem/10304224>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142390 91177308-0d34-0410-b5e6-96231b3b80d8