Without this we would have multiple relocations pointing to symbols
with the same name: the empty string. There was no way for yaml2obj to
be able to handle that.
A more general solution would be to unique symbol names in a similar
way to how we unique section names. In practice I think this covers
all common cases and is a bit more user friendly than using names like
sym1, sym2, sym3, etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312603 91177308-0d34-0410-b5e6-96231b3b80d8