Reapply r110396, with fixes to appease the Linux buildbot gods.

llvm-svn: 110460

llvm/lib/CodeGen/MachineLoopInfo.cpp

@@ -33,7 +33,7 @@ char MachineLoopInfo::ID = 0;
 static RegisterPass<MachineLoopInfo>
 X("machine-loops", "Machine Natural Loop Construction", true);
 
-const PassInfo *const llvm::MachineLoopInfoID = &X;
+char &llvm::MachineLoopInfoID = MachineLoopInfo::ID;
 
 bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) {
   releaseMemory();