Silence unused variable warnings.

Swift SVN r23346

lib/SILAnalysis/CallGraphAnalysis.cpp

@@ -90,6 +90,7 @@ void CallGraph::addEdgesForApply(ApplyInst *AI, CallGraphNode *CallerNode) {
     auto ThinCallee = cast<ThinToThickFunctionInst>(Callee)->getOperand();
     // TODO: We want to see through these to the underlying function.
     assert(cast<FunctionRefInst>(ThinCallee) && "Expected function reference!");
+    (void)ThinCallee;
     ++NumCallSitesWithoutEdges;
     break;
   }

lib/SILGen/SILGenExpr.cpp

@@ -1404,6 +1404,8 @@ static void buildBlockToFuncThunkBody(SILGenFunction &gen,
            ? convention == ResultConvention::Unowned
            : convention == ResultConvention::Owned)
          && "nonstandard conventions for return not implemented");
+  (void)convention;
+  (void)resultTL;
   
   auto r = result.forward(gen);
   scope.pop();

lib/Sema/TypeCheckProtocol.cpp

@@ -2447,6 +2447,7 @@ static bool existentialConformsToProtocol(TypeChecker &tc, Type type,
   SmallVector<ProtocolDecl *, 4> protocols;
   bool isExistential = type->isExistentialType(protocols);
   assert(isExistential && "Not existential?");
+  (void)isExistential;
 
   // An existential that must be a class trivially conforms to AnyObject.
   if (type->isClassExistentialType() &&