[ARM] 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: t.p.northover, RKSimon, MatzeB, bkramer

Reviewed By: bkramer

Subscribers: javed.absar, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D44855

llvm-svn: 329329
diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index d39aaf8..cc44c70 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1407,12 +1407,12 @@
   SmallVector<unsigned, 6> ScratchRegs;
   for(unsigned I = 5; I < MI->getNumOperands(); ++I)
     ScratchRegs.push_back(MI->getOperand(I).getReg());
-  std::sort(ScratchRegs.begin(), ScratchRegs.end(),
-            [&TRI](const unsigned &Reg1,
-                   const unsigned &Reg2) -> bool {
-              return TRI.getEncodingValue(Reg1) <
-                     TRI.getEncodingValue(Reg2);
-            });
+  llvm::sort(ScratchRegs.begin(), ScratchRegs.end(),
+             [&TRI](const unsigned &Reg1,
+                    const unsigned &Reg2) -> bool {
+               return TRI.getEncodingValue(Reg1) <
+                      TRI.getEncodingValue(Reg2);
+             });
 
   for (const auto &Reg : ScratchRegs) {
     LDM.addReg(Reg, RegState::Define);