Use std::make_pair instead of std::pair's ctor.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60205 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicStore.cpp b/lib/Analysis/BasicStore.cpp
index 7238d5b..e98975d 100644
--- a/lib/Analysis/BasicStore.cpp
+++ b/lib/Analysis/BasicStore.cpp
@@ -68,7 +68,7 @@
 
   std::pair<const GRState*, SVal> 
   CastRegion(const GRState* St, SVal VoidPtr, QualType CastToTy, Stmt* CastE) {
-    return std::pair<const GRState*, SVal>(St, UnknownVal());
+    return std::make_pair(St, UnknownVal());
   }