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/Scalar/GCSE.cpp

@@ -51,7 +51,7 @@ namespace {
 
     // This transformation requires dominator and immediate dominator info
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      //preservesCFG(AU);
+      AU.preservesCFG();
       AU.addRequired(DominatorSet::ID);
       AU.addRequired(ImmediateDominators::ID); 
     }