[X86] 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: chandlerc, craig.topper, RKSimon

Reviewed By: chandlerc, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44874

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329534 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ISelLowering.cpp

@@ -11679,11 +11679,11 @@ static SDValue lowerV8I16GeneralSingleInputVectorShuffle(
 
   SmallVector<int, 4> LoInputs;
   copy_if(LoMask, std::back_inserter(LoInputs), [](int M) { return M >= 0; });
-  std::sort(LoInputs.begin(), LoInputs.end());
+  array_pod_sort(LoInputs.begin(), LoInputs.end());
   LoInputs.erase(std::unique(LoInputs.begin(), LoInputs.end()), LoInputs.end());
   SmallVector<int, 4> HiInputs;
   copy_if(HiMask, std::back_inserter(HiInputs), [](int M) { return M >= 0; });
-  std::sort(HiInputs.begin(), HiInputs.end());
+  array_pod_sort(HiInputs.begin(), HiInputs.end());
   HiInputs.erase(std::unique(HiInputs.begin(), HiInputs.end()), HiInputs.end());
   int NumLToL =
       std::lower_bound(LoInputs.begin(), LoInputs.end(), 4) - LoInputs.begin();
@@ -12486,12 +12486,12 @@ static SDValue lowerV16I8VectorShuffle(const SDLoc &DL, ArrayRef<int> Mask,
       SmallVector<int, 4> LoInputs;
       copy_if(Mask, std::back_inserter(LoInputs),
               [](int M) { return M >= 0 && M < 8; });
-      std::sort(LoInputs.begin(), LoInputs.end());
+      array_pod_sort(LoInputs.begin(), LoInputs.end());
       LoInputs.erase(std::unique(LoInputs.begin(), LoInputs.end()),
                      LoInputs.end());
       SmallVector<int, 4> HiInputs;
       copy_if(Mask, std::back_inserter(HiInputs), [](int M) { return M >= 8; });
-      std::sort(HiInputs.begin(), HiInputs.end());
+      array_pod_sort(HiInputs.begin(), HiInputs.end());
       HiInputs.erase(std::unique(HiInputs.begin(), HiInputs.end()),
                      HiInputs.end());