Don't recalculate the loop info and loop dominators analyses if they're
preserved.

llvm-svn: 45596
diff --git a/llvm/lib/CodeGen/MachineDominators.cpp b/llvm/lib/CodeGen/MachineDominators.cpp
index e343240..7c521cc 100644
--- a/llvm/lib/CodeGen/MachineDominators.cpp
+++ b/llvm/lib/CodeGen/MachineDominators.cpp
@@ -13,12 +13,17 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/Passes.h"
 
 using namespace llvm;
 
 TEMPLATE_INSTANTIATION(class DomTreeNodeBase<MachineBasicBlock>);
 TEMPLATE_INSTANTIATION(class DominatorTreeBase<MachineBasicBlock>);
 
-char MachineDominatorTree::ID = 0;
-static RegisterPass<MachineDominatorTree>
-E("machinedomtree", "MachineDominator Tree Construction", true);
+namespace {
+  char MachineDominatorTree::ID = 0;
+  RegisterPass<MachineDominatorTree>
+  E("machinedomtree", "MachineDominator Tree Construction", true);
+}
+
+const PassInfo *llvm::MachineDominatorsID = E.getPassInfo();