[GVNHoist] Fix a signed/unsigned comparison warning that occurs in 32-bit builds with gcc.

std::distance returns ptrdiff_t which is signed. 64-bit builds don't notice because type promotion widens the unsigned first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318354 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed