Squash release build warnings (#18986)

Author: airspeedswift

lib/ClangImporter/ImportDecl.cpp

@@ -7690,6 +7690,7 @@ static void finishInheritedConformances(
                                                      inherited);
     assert(inheritedConformance && inheritedConformance->isConcrete() &&
            "inherited conformance not found");
+    (void)inheritedConformance;
   }
 }
 

lib/SILGen/SILGenPoly.cpp

@@ -2597,8 +2597,9 @@ ResultPlanner::planScalarFromIndirectResult(AbstractionPattern innerOrigType,
 void ResultPlanner::executeInnerTuple(
     SILValue innerElement, SmallVector<SILValue, 4> &innerDirectResults) {
   // NOTE: We know that our value is at +1 here.
-  auto innerTupleType = innerElement->getType().getAs<TupleType>();
-  assert(innerTupleType && "Only supports tuple inner types");
+  assert(innerElement->getType().getAs<TupleType>() &&
+         "Only supports tuple inner types");
+
   SGF.B.emitDestructureValueOperation(
       Loc, innerElement, [&](unsigned index, SILValue elt) {
         if (elt->getType().is<TupleType>())

lib/SILOptimizer/Transforms/SpeculativeDevirtualizer.cpp

@@ -218,9 +218,8 @@ static FullApplySite speculateMonomorphicTarget(FullApplySite AI,
   NumTargetsPredicted++;
 
   // Devirtualize the apply instruction on the identical path.
-  auto NewInst =
-      devirtualizeClassMethod(IdenAI, DownCastedClassInstance, nullptr);
-  assert(NewInst && "Expected to be able to devirtualize apply!");
+  assert(devirtualizeClassMethod(IdenAI, DownCastedClassInstance, nullptr) &&
+         "Expected to be able to devirtualize apply!");
   deleteDevirtualizedApply(IdenAI);
 
   // Split critical edges resulting from VirtAI.