Remove "#if 0"ed out assert

Remove "#if 0"ed out assert

It won't compile after the recent changes I've made, and I think
keeping it in provides very little value.

Instead I've added (in an earlier commit) a C++ unit test to check the
Denormalize(Normalized(X)) == X property for specific instances of X,
which is what the assert was trying to do anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300339 91177308-0d34-0410-b5e6-96231b3b80d8