Firstly, make Get*Buffer() methodRemove most of the abstract, rather than defining themion over ptrace() register operations,
to return NULL. They are going to be redefined in majority (if not all)as it has little value and introduces more code than it saves.
arches and if we ever need to skip them somewhereInstead, it's better toleave a single ptrace() wrapper method and call it directly
define it as llvm_unreachable(). Appropriately, remove unnecessaryfrom ReadRegisterSet() and WriteRegisterSet() with correct PT_* request
NULL checks from Read*() and Write*() functionsand buffer.
Secondly,Remove the remove GetFPRSize() and GetDPRSize() methods. They are neveraining direct ReadGPR() and WriteGPR() invocations
used, nor implementedwith ReadRegisterSet() and WriteRegisterSet().
Cleanup suggested by Pavel Labath in D63545.