[SystemZ] Update non-pic DWARF encodings

[SystemZ] Update non-pic DWARF encodings

As pointed out by Rafael Espindola, we should match the DWARF encodings
produced by GCC in both pic and non-pic modes.  This was not the case
for the non-pic case.

This patch changes all DWARF encodings to DW_EH_PE_absptr for the
non-pic case, just like GCC does.  The test case is updated to check
for both variants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181222 91177308-0d34-0410-b5e6-96231b3b80d8