[codeview] Fix DenseMap pointer invalidation bug

When you have a map holding a unique_ptr, hold a reference to the raw
pointer instead of the unique pointer. The unique_ptr will be moved on
rehash.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273268 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed