Squash some unused variable warnings

Author: slavapestov

lib/IDE/CodeCompletion.cpp

@@ -4024,7 +4024,7 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
       }
 
       return getPositionInTupleExpr(DC, CCExpr, tuple, Position, HasName);
-    } else if (auto *paren = dyn_cast<ParenExpr>(CallE->getArg())) {
+    } else if (isa<ParenExpr>(CallE->getArg())) {
       HasName = false;
       Position = 0;
       return true;

lib/IRGen/LoadableByAddress.cpp

@@ -123,7 +123,7 @@ static bool containsFunctionSignature(GenericEnvironment *genEnv,
       if (auto optionalObject = objectType.getOptionalObjectType()) {
         objectType = optionalObject;
       }
-      if (auto fnType = objectType.getAs<SILFunctionType>()) {
+      if (objectType.is<SILFunctionType>()) {
         return true;
       }
     }

lib/SIL/InstructionUtils.cpp

@@ -537,7 +537,7 @@ FindClosureResult swift::findClosureForAppliedArg(SILValue V) {
   if (auto *bbi = dyn_cast<BeginBorrowInst>(V))
     V = bbi->getOperand();
 
-  if (auto optionalObjTy = V->getType().getOptionalObjectType())
+  if (V->getType().getOptionalObjectType())
     V = cast<EnumInst>(V)->getOperand();
 
   auto fnType = V->getType().getAs<SILFunctionType>();

lib/SILOptimizer/Mandatory/DiagnoseStaticExclusivity.cpp

@@ -1041,7 +1041,7 @@ static void checkNoEscapePartialApply(PartialApplyInst *PAI) {
       uses.append(EI->getUses().begin(), EI->getUses().end());
       continue;
     }
-    if (auto apply = isa<ApplySite>(user)) {
+    if (isa<ApplySite>(user)) {
       SILValue arg = oper->get();
       auto ArgumentFnType = getSILFunctionTypeForValue(arg);
       if (ArgumentFnType && ArgumentFnType->isNoEscape()) {