[AliasSet] Fix UnknownInstructions printing

[kuhar]

Summary

AliasSet::print uses I->printAsOperand to print UnknownInstructions. The problem is that not all UnknownInstructions have names (e.g. call instructions). When such instructions are printed, they appear as <badref> in AliasSets, which is very confusing, as the values are perfectly valid.

This patch fixes that by printing UnknownInstructions without a name using print instead of printAsOperand.

[asbirlea]

LGTM.

llvm/trunk/lib/Analysis/AliasSetTracker.cpp

for (iterator I = begin(), E = end(); I != E; ++I) {
       I.getPointer()->printAsOperand(OS << "(");
       OS << ", " << I.getSize() << ")";
     }
   }
   if (!UnknownInsts.empty()) {
     OS << "\n    " << UnknownInsts.size() << " Unknown instructions: ";
     for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) {
       if (i) OS << ", ";
-      if (auto *I = getUnknownInst(i))
+      if (auto *I = getUnknownInst(i)) {
+        if (I->hasName())
           I->printAsOperand(OS);
+        else
+          I->print(OS);
+      }
     }
   }
   OS << "\n";
 }
 
 void AliasSetTracker::print(raw_ostream &OS) const {
   OS << "Alias Set Tracker: " << AliasSets.size() << " alias sets for "
      << PointerMap.size() << " pointer values.\n";