[RuntimeDyld] Support more PPC64 relocations

This adds support for several missing PPC64 relocations in the
straight-forward manner to RuntimeDyldELF.cpp.

Note that this actually fixes a failure of a large-model test case on
PowerPC, allowing the XFAIL to be removed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211382 91177308-0d34-0410-b5e6-96231b3b80d8