Fix SFINAE in CFG.cpp.

[jlebar]

Summary

Used std::enable_if without ::type.

[jlebar]

Rebase

[bkramer]

lg

clang/lib/Analysis/CFG.cpp

private:
   // is found, the function recurses into that.
   void findConstructionContexts(const ConstructionContextLayer *Layer,
                                 Stmt *Child);
 
   // Scan all arguments of a call expression for a construction context.
   // These sorts of call expressions don't have a common superclass,
   // hence strict duck-typing.
   template <typename CallLikeExpr,
-            typename = typename std::enable_if<
-                std::is_same<CallLikeExpr, CallExpr>::value ||
-                std::is_same<CallLikeExpr, CXXConstructExpr>::value ||
-                std::is_same<CallLikeExpr, ObjCMessageExpr>::value>>
+            typename = std::enable_if_t<
+                std::is_base_of<CallExpr, CallLikeExpr>::value ||
+                std::is_base_of<CXXConstructExpr, CallLikeExpr>::value ||
+                std::is_base_of<ObjCMessageExpr, CallLikeExpr>::value>>
   void findConstructionContextsForArguments(CallLikeExpr *E) {
     for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) {
       Expr *Arg = E->getArg(i);
       if (Arg->getType()->getAsCXXRecordDecl() && !Arg->isGLValue())
         findConstructionContexts(
             ConstructionContextLayer::create(cfg->getBumpVectorContext(),
                                              ConstructionContextItem(E, i)),
             Arg);