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

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.

llvm-svn: 328636
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 2748dc3..e1cb324 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1294,7 +1294,7 @@
     AddedAttr = true;
   }
   if (!Features.empty()) {
-    std::sort(Features.begin(), Features.end());
+    llvm::sort(Features.begin(), Features.end());
     Attrs.addAttribute("target-features", llvm::join(Features, ","));
     AddedAttr = true;
   }