Insert explicit casts to try appease overload resolution in the buildbots

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182514 91177308-0d34-0410-b5e6-96231b3b80d8

lib/StaticAnalyzer/Core/BugReporter.cpp

@@ -2016,7 +2016,7 @@ static void removePunyEdges(PathPieces &path,
     if (Invalid)
       continue;
 
-    if (::abs(startCol - endCol) <= 2) {
+    if (abs((int)startCol - (int)endCol) <= 2) {
       I = path.erase(I);
       erased = true;
       continue;