[Bitcode] Change std::sort to llvm::sort in response to r327219

[mgrang]

Summary

r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.

Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.

[dexonsmith]

LGTM.

llvm/trunk/lib/Bitcode/Reader/ValueList.cpp

 /// references.  The idea behind this is that we sometimes get constants (such
 /// as large arrays) which reference *many* forward ref constants.  Replacing
 /// each of these causes a lot of thrashing when building/reuniquing the
 /// constant.  Instead of doing this, we look at all the uses and rewrite all
 /// the place holders at once for any constant that uses a placeholder.
 void BitcodeReaderValueList::resolveConstantForwardRefs() {
   // Sort the values by-pointer so that they are efficient to look up with a
   // binary search.
-  std::sort(ResolveConstants.begin(), ResolveConstants.end());
+  llvm::sort(ResolveConstants.begin(), ResolveConstants.end());
 
   SmallVector<Constant *, 64> NewOps;
 
   while (!ResolveConstants.empty()) {
     Value *RealVal = operator[](ResolveConstants.back().second);
     Constant *Placeholder = ResolveConstants.back().first;
     ResolveConstants.pop_back();
 

llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp

void ModuleBitcodeWriterBase::writeModuleLevelReferences(
   GlobalVarSummary *VS = cast<GlobalVarSummary>(Summary);
   NameVals.push_back(getEncodedGVSummaryFlags(VS->flags()));
 
   unsigned SizeBeforeRefs = NameVals.size();
   for (auto &RI : VS->refs())
     NameVals.push_back(VE.getValueID(RI.getValue()));
   // Sort the refs for determinism output, the vector returned by FS->refs() has
   // been initialized from a DenseSet.
-  std::sort(NameVals.begin() + SizeBeforeRefs, NameVals.end());
+  llvm::sort(NameVals.begin() + SizeBeforeRefs, NameVals.end());
 
   Stream.EmitRecord(bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS, NameVals,
                     FSModRefsAbbrev);
   NameVals.clear();
 }
 
 // Current version for the summary.
 // This is bumped whenever we introduce changes in the way some record are

llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp

for (const Use &U : V->uses())
     if (OM.lookup(U.getUser()).first)
       List.push_back(std::make_pair(&U, List.size()));
 
   if (List.size() < 2)
     // We may have lost some users.
     return;
 
   bool IsGlobalValue = OM.isGlobalValue(ID);
-  std::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
+  llvm::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
     const Use *LU = L.first;
     const Use *RU = R.first;
     if (LU == RU)
       return false;
 
     auto LID = OM.lookup(LU->getUser()).first;
     auto RID = OM.lookup(RU->getUser()).first;
 
for (const Metadata *MD : MDs)
     Order.push_back(MetadataMap.lookup(MD));
 
   // Partition:
   //   - by function, then
   //   - by isa<MDString>
   // and then sort by the original/current ID.  Since the IDs are guaranteed to
   // be unique, the result of std::sort will be deterministic.  There's no need
   // for std::stable_sort.
-  std::sort(Order.begin(), Order.end(), [this](MDIndex LHS, MDIndex RHS) {
+  llvm::sort(Order.begin(), Order.end(), [this](MDIndex LHS, MDIndex RHS) {
     return std::make_tuple(LHS.F, getMetadataTypeOrder(LHS.get(MDs)), LHS.ID) <
            std::make_tuple(RHS.F, getMetadataTypeOrder(RHS.get(MDs)), RHS.ID);
   });
 
   // Rebuild MDs, index the metadata ranges for each function in FunctionMDs,
   // and fix up MetadataMap.
   std::vector<const Metadata *> OldMDs = std::move(MDs);
   MDs.reserve(OldMDs.size());