Use the range variant of find instead of unpacking begin/end

If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

llvm-svn: 278433
diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
index 8fdf39d..bf61ee0 100644
--- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
@@ -245,7 +245,7 @@
       // Remember source that's copied to Def. Once it's clobbered, then
       // it's no longer available for copy propagation.
       RegList &DestList = SrcMap[Src];
-      if (std::find(DestList.begin(), DestList.end(), Def) == DestList.end())
+      if (!is_contained(DestList, Def))
         DestList.push_back(Def);
 
       continue;