Set the branch probability of branching to the 'normal' destination of an invoke

Set the branch probability of branching to the 'normal' destination of an invoke
instruction to something absurdly high, while setting the probability of
branching to the 'unwind' destination to the bare minimum. This should set cause
the normal destination's invoke blocks to be moved closer to the invoke.

PR13612

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161944 91177308-0d34-0410-b5e6-96231b3b80d8