Tighten up the AnalysisUsage of lots of passes, primarily to correctly indicate whether or not they invalidate the CFGA

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2386 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/ConstantMerge.cpp

@@ -82,6 +82,10 @@ namespace {
       Constants.clear();
       return false;
     }
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+      AU.setPreservesAll();
+    }
   };
   
   struct DynamicConstantMerge : public ConstantMerge {