[CodeGen] 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 the comments section in D44363 for a list of all the required patches.

Reviewers: bogner, rnk, MatzeB, RKSimon

Reviewed By: rnk

Subscribers: JDevlieghere, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D45133

llvm-svn: 329435
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index 7a201bc..061d971 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -931,7 +931,7 @@
     }
   });
 
-  std::sort(NodeSets.begin(), NodeSets.end(), std::greater<NodeSet>());
+  llvm::sort(NodeSets.begin(), NodeSets.end(), std::greater<NodeSet>());
 
   groupRemainingNodes(NodeSets);
 
@@ -1863,7 +1863,8 @@
     RecRPTracker.closeBottom();
 
     std::vector<SUnit *> SUnits(NS.begin(), NS.end());
-    std::sort(SUnits.begin(), SUnits.end(), [](const SUnit *A, const SUnit *B) {
+    llvm::sort(SUnits.begin(), SUnits.end(),
+               [](const SUnit *A, const SUnit *B) {
       return A->NodeNum > B->NodeNum;
     });
 
@@ -3980,7 +3981,7 @@
   };
 
   // sort, so that we can perform a binary search
-  std::sort(Indices.begin(), Indices.end(), CompareKey);
+  llvm::sort(Indices.begin(), Indices.end(), CompareKey);
 
   bool Valid = true;
   (void)Valid;