[TSan] Refactor/simplify ReportLocation structure.

  # Make DataInfo (describing a global) a member of ReportLocation
    to avoid unnecessary copies and allocations.
  # Introduce a constructor and a factory method, so that
    all structure users don't have to go to internal allocator directly.
  # Remove unused fields (file/line).

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@221302 91177308-0d34-0410-b5e6-96231b3b80d8