[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/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 99e7615..f8fad02 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -456,10 +456,10 @@
 }
 
 void MachineBasicBlock::sortUniqueLiveIns() {
-  std::sort(LiveIns.begin(), LiveIns.end(),
-            [](const RegisterMaskPair &LI0, const RegisterMaskPair &LI1) {
-              return LI0.PhysReg < LI1.PhysReg;
-            });
+  llvm::sort(LiveIns.begin(), LiveIns.end(),
+             [](const RegisterMaskPair &LI0, const RegisterMaskPair &LI1) {
+               return LI0.PhysReg < LI1.PhysReg;
+             });
   // Liveins are sorted by physreg now we can merge their lanemasks.
   LiveInVector::const_iterator I = LiveIns.begin();
   LiveInVector::const_iterator J;