NFC: Address some unused variable warnings.

Author: tshortli

lib/IRGen/GenCall.cpp

@@ -4995,8 +4995,6 @@ void IRGenFunction::emitEpilogue() {
     CurFn->addFnAttr(llvm::Attribute::getWithUWTableKind(
         *IGM.LLVMContext, llvm::UWTableKind::Default));
 
-    auto deploymentAvailability =
-      AvailabilityContext::forDeploymentTarget(IGM.Context);
     llvm::Constant *personality;
 
     if (IGM.isSwiftExceptionPersonalityFeatureAvailable()) {

lib/SILGen/SILGenPoly.cpp

@@ -4495,7 +4495,6 @@ void ResultPlanner::planExpandedIntoDirect(AbstractionPattern innerOrigType,
       assert(outerSubstType->isAny());
 
       auto *module = SGF.getModule().getSwiftModule();
-      auto &ctx = SGF.getASTContext();
 
       auto opaque = AbstractionPattern::getOpaque();
       auto anyType = SGF.getLoweredType(opaque, outerSubstType);

lib/SILOptimizer/Mandatory/ConsumeOperatorCopyableAddressesChecker.cpp

@@ -2461,7 +2461,6 @@ class ConsumeOperatorCopyableAddressesCheckerPass
     : public SILFunctionTransform {
   void run() override {
     auto *fn = getFunction();
-    auto &astContext = fn->getASTContext();
 
     // Don't rerun diagnostics on deserialized functions.
     if (getFunction()->wasDeserializedCanonical())