This patch teaches FunctionInfo about offsets.
Like the last patch, this one doesn't introduce any visible
functionality change (the core algorithm knows nothing about offsets;
they're just plumbed through). Tests will come when we start acting
differently because of the offsets.
Patch by Jia Chen.
(N.B. I made a tiny change to Jia's patch to avoid warnings by GCC: I
put DenseMapInfo specializations in the `llvm` namespace. Only realized
that those appeared when compiling locally. :) )
Differential Revision: https://reviews.llvm.org/D22634
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276486 91177308-0d34-0410-b5e6-96231b3b80d8
