[PM] Don't spend time making self moves no-ops. They're allowed to leave

the object in a moved-from state, and its simpler to write the code that
way.

llvm-svn: 226589

Author: chandlerc

llvm/include/llvm/Analysis/LoopInfo.h

@@ -514,14 +514,12 @@ class LoopInfoBase {
     Arg.TopLevelLoops.clear();
   }
   LoopInfoBase &operator=(LoopInfoBase &&RHS) {
-    if (&RHS != this) {
-      BBMap = std::move(RHS.BBMap);
+    BBMap = std::move(RHS.BBMap);
 
-      for (auto *L : TopLevelLoops)
-        delete L;
-      TopLevelLoops = std::move(RHS.TopLevelLoops);
-      RHS.TopLevelLoops.clear();
-    }
+    for (auto *L : TopLevelLoops)
+      delete L;
+    TopLevelLoops = std::move(RHS.TopLevelLoops);
+    RHS.TopLevelLoops.clear();
     return *this;
   }