Allow CallSites to be used as the key of a map

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9660 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/CallSite.h

@@ -83,6 +83,10 @@ public:
       return I->op_begin()+3; // Skip Function, BB, BB
   }
   arg_iterator arg_end() const { return I->op_end(); }
+
+  bool operator<(const CallSite &CS) const {
+    return getInstruction() < CS.getInstruction();
+  }
 };
 
 #endif