[ModuleSummaryAnalysis] Don't crash when referencing unnamed globals.

Instead, just be conservative as these are unfrequent enough. Thanks
to Peter Collingbourne for the discussion about this on IRC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295861 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ModuleSummaryAnalysis.cpp

@@ -447,6 +447,12 @@ ModuleSummaryIndex llvm::buildModuleSummaryIndex(
     auto &Summary = GlobalList.second[0];
     bool AllRefsCanBeExternallyReferenced =
         llvm::all_of(Summary->refs(), [&](const ValueInfo &VI) {
+          // If a global value definition references an unnamed global,
+          // be conservative. They're valid IR so we don't want to crash
+          // when we encounter any of them but they're infrequent enough
+          // that we don't bother optimizing them.
+          if (!VI.getValue()->hasName())
+            return false;
           return !CantBePromoted.count(VI.getValue()->getGUID());
         });
     if (!AllRefsCanBeExternallyReferenced) {