[Sanitizer][PassManager] Fix for failing ASan tests on ARM

[leonardchan]

Summary

Forgot to initialize the legacy pass in it's constructor.

[dyung]

I'm not sure that I'm the best person to review this change as I am not really familiar with this area, but I can confirm that when I apply your patch locally it does fix the problem I was seeing, and the change looks reasonable to me.

llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

 class AddressSanitizerLegacyPass : public FunctionPass {
 public:
   static char ID;
 
   explicit AddressSanitizerLegacyPass(bool CompileKernel = false,
                                       bool Recover = false,
                                       bool UseAfterScope = false)
       : FunctionPass(ID), CompileKernel(CompileKernel), Recover(Recover),
-        UseAfterScope(UseAfterScope) {}
+        UseAfterScope(UseAfterScope) {
+    initializeAddressSanitizerLegacyPassPass(*PassRegistry::getPassRegistry());
+  }
 
   StringRef getPassName() const override {
     return "AddressSanitizerFunctionPass";
   }
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addRequired<TargetLibraryInfoWrapperPass>();