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

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 D44363 for a list of all the required patches.

Reviewers: pcc, mehdi_amini, ruiu

Reviewed By: ruiu

Subscribers: ruiu, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D45137

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330053 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Mandeep Singh Grang

lib/LTO/ThinLTOCodeGenerator.cpp

@@ -947,12 +947,12 @@ void ThinLTOCodeGenerator::run() {
   std::vector<int> ModulesOrdering;
   ModulesOrdering.resize(Modules.size());
   std::iota(ModulesOrdering.begin(), ModulesOrdering.end(), 0);
-  std::sort(ModulesOrdering.begin(), ModulesOrdering.end(),
-            [&](int LeftIndex, int RightIndex) {
-              auto LSize = Modules[LeftIndex].getBuffer().size();
-              auto RSize = Modules[RightIndex].getBuffer().size();
-              return LSize > RSize;
-            });
+  llvm::sort(ModulesOrdering.begin(), ModulesOrdering.end(),
+             [&](int LeftIndex, int RightIndex) {
+               auto LSize = Modules[LeftIndex].getBuffer().size();
+               auto RSize = Modules[RightIndex].getBuffer().size();
+               return LSize > RSize;
+             });
 
   // Parallel optimizer + codegen
   {