Introduce print-memderefs to test isDereferenceablePointer

Since testing the function indirectly is tricky, introduce a direct
print-memderefs pass, in the same spirit as print-memdeps, which prints
dereferenceability information matched by FileCheck.

Differential Revision: http://reviews.llvm.org/D7075

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228369 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/Analysis.cpp

@@ -55,6 +55,7 @@ void llvm::initializeAnalysis(PassRegistry &Registry) {
   initializeLintPass(Registry);
   initializeLoopInfoWrapperPassPass(Registry);
   initializeMemDepPrinterPass(Registry);
+  initializeMemDerefPrinterPass(Registry);
   initializeMemoryDependenceAnalysisPass(Registry);
   initializeModuleDebugInfoPrinterPass(Registry);
   initializePostDominatorTreePass(Registry);