Allow operator-> to work from a FixedStreamArrayIterator.

This is similar to my recent fix for VarStreamArrayIterator, but the cause
(and thus the fix) is subtley different.  The FixedStreamArrayIterator
iterates over a const Array, so the iterator's value type must be const.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302257 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed