message: Add XCOFF triple object format type for AIX
  This patch adds an XCOFF triple object format type into LLVM.
  This XCOFF triple object file type will be used later by object file and assembly generation for the AIX platform.
diff: @@ -2059,6 +2059,7 @@ bool GDBRemoteCommunicationClient::GetCurrentProcessInfo(bool allow_lazy) {
  assert(triple.getObjectFormat() != llvm::Triple::UnknownObjectFormat);
  assert(triple.getObjectFormat() != llvm::Triple::Wasm);
  + assert(triple.getObjectFormat() != llvm::Triple::XCOFF);
  switch (triple.getObjectFormat()) {
  case llvm::Triple::MachO:
  m_process_arch.SetArchitecture(eArchTypeMachO, cpu, sub);
  @@ -2070,6 +2071,7 @@ bool GDBRemoteCommunicationClient::GetCurrentProcessInfo(bool allow_lazy) {
  m_process_arch.SetArchitecture(eArchTypeCOFF, cpu, sub);
  break;
  case llvm::Triple::Wasm:
  + case llvm::Triple::XCOFF:
  if (log)
  log->Printf("error: not supported target architecture");
  return false;
  