Remove the deprecated and unused startAsyncLet builtin

Author: rjmccall

include/swift/AST/Builtins.def

@@ -885,17 +885,7 @@ BUILTIN_MISC_OPERATION_WITH_SILGEN(GetCurrentAsyncTask, "getCurrentAsyncTask", "
 /// Cancel the given asynchronous task.
 BUILTIN_MISC_OPERATION_WITH_SILGEN(CancelAsyncTask, "cancelAsyncTask", "", Special)
 
-/// startAsyncLet()<T>: (
-///     __owned @escaping () async throws -> sending T
-/// ) -> Builtin.RawPointer
-///
-/// DEPRECATED. startAsyncLetWithLocalBuffer is used instead.
-///
-/// Create, initialize and start a new async-let and associated task.
-/// Returns an AsyncLet* that must be passed to endAsyncLet for destruction.
-BUILTIN_MISC_OPERATION(StartAsyncLet, "startAsyncLet", "", Special)
-
-/// startAsyncLetWithLocalBuffer()<T>: (
+/// startAsyncLetWithLocalBuffer: <T> (
 ///     __owned @escaping () async throws -> sending T,
 ///     _ resultBuf: Builtin.RawPointer
 /// ) -> Builtin.RawPointer

lib/AST/Builtins.cpp

@@ -3379,7 +3379,6 @@ ValueDecl *swift::getBuiltinValueDecl(ASTContext &Context, Identifier Id) {
   case BuiltinValueKind::InitializeDistributedRemoteActor:
     return getDistributedActorInitializeRemote(Context, Id);
 
-  case BuiltinValueKind::StartAsyncLet:
   case BuiltinValueKind::StartAsyncLetWithLocalBuffer:
     return getStartAsyncLet(Context, Id);
 

lib/IRGen/GenBuiltin.cpp

@@ -279,26 +279,6 @@ void irgen::emitBuiltinCall(IRGenFunction &IGF, const BuiltinInfo &Builtin,
     return;
   }
 
-  case BuiltinValueKind::StartAsyncLet: {
-    auto taskOptions = args.claimNext();
-    auto taskFunction = args.claimNext();
-    auto taskContext = args.claimNext();
-    taskOptions = IGF.Builder.CreateIntToPtr(taskOptions,
-                                             IGF.IGM.SwiftTaskOptionRecordPtrTy);
-
-    auto asyncLet = emitBuiltinStartAsyncLet(
-        IGF,
-        taskOptions,
-        taskFunction,
-        taskContext,
-        nullptr,
-        substitutions
-        );
-
-    out.add(asyncLet);
-    return;
-  }
-
   case BuiltinValueKind::StartAsyncLetWithLocalBuffer: {
     auto taskOptions = args.claimNext();
     auto taskFunction = args.claimNext();

lib/IRGen/PackMetadataMarkerInserter.cpp

@@ -88,8 +88,7 @@ Inserter::shouldInsertMarkersForInstruction(SILInstruction *inst) {
     // SIL.  As a result, stack nesting is unable to properly nest async lets
     // with on-stack pack metadata.  rdar://109850951
     if (bi->getBuiltinKind() ==
-            BuiltinValueKind::StartAsyncLetWithLocalBuffer ||
-        bi->getBuiltinKind() == BuiltinValueKind::StartAsyncLet)
+            BuiltinValueKind::StartAsyncLetWithLocalBuffer)
       return Inserter::FindResult::Unhandleable;
     LLVM_FALLTHROUGH;
   }

lib/SIL/IR/OperandOwnership.cpp

@@ -941,7 +941,6 @@ BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, GetEnumTag)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, InjectEnumTag)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, DistributedActorAsAnyActor)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, AddressOfRawLayout)
-BUILTIN_OPERAND_OWNERSHIP(DestroyingConsume, StartAsyncLet)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, EndAsyncLet)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, EndAsyncLetLifetime)
 BUILTIN_OPERAND_OWNERSHIP(InstantaneousUse, CreateTaskGroup)

lib/SIL/IR/ValueOwnership.cpp

@@ -649,7 +649,6 @@ CONSTANT_OWNERSHIP_BUILTIN(None, BuildOrdinarySerialExecutorRef)
 CONSTANT_OWNERSHIP_BUILTIN(None, BuildComplexEqualitySerialExecutorRef)
 CONSTANT_OWNERSHIP_BUILTIN(None, BuildDefaultActorExecutorRef)
 CONSTANT_OWNERSHIP_BUILTIN(None, BuildMainActorExecutorRef)
-CONSTANT_OWNERSHIP_BUILTIN(None, StartAsyncLet)
 CONSTANT_OWNERSHIP_BUILTIN(None, EndAsyncLet)
 CONSTANT_OWNERSHIP_BUILTIN(None, StartAsyncLetWithLocalBuffer)
 CONSTANT_OWNERSHIP_BUILTIN(None, EndAsyncLetLifetime)

lib/SIL/Utils/InstructionUtils.cpp

@@ -1124,7 +1124,6 @@ RuntimeEffect swift::getRuntimeEffect(SILInstruction *inst, SILType &impactType)
     case BuiltinValueKind::BuildComplexEqualitySerialExecutorRef:
     case BuiltinValueKind::BuildDefaultActorExecutorRef:
     case BuiltinValueKind::BuildMainActorExecutorRef:
-    case BuiltinValueKind::StartAsyncLet:
     case BuiltinValueKind::StartAsyncLetWithLocalBuffer:
       return RuntimeEffect::MetaData;
     default:

lib/SIL/Utils/MemAccessUtils.cpp

@@ -2654,7 +2654,6 @@ static void visitBuiltinAddress(BuiltinInst *builtin,
     case BuiltinValueKind::InitializeNonDefaultDistributedActor:
     case BuiltinValueKind::DestroyDefaultActor:
     case BuiltinValueKind::GetCurrentExecutor:
-    case BuiltinValueKind::StartAsyncLet:
     case BuiltinValueKind::StartAsyncLetWithLocalBuffer:
     case BuiltinValueKind::EndAsyncLet:
     case BuiltinValueKind::EndAsyncLetLifetime:

lib/SILGen/SILGen.cpp

@@ -385,10 +385,6 @@ static FuncDecl *lookupConcurrencyIntrinsic(ASTContext &C, StringRef name) {
       /*default=*/nullptr);
 }
 
-FuncDecl *SILGenModule::getAsyncLetStart() {
-  return lookupConcurrencyIntrinsic(getASTContext(), "_asyncLetStart");
-}
-
 FuncDecl *SILGenModule::getAsyncLetGet() {
   return lookupConcurrencyIntrinsic(getASTContext(), "_asyncLet_get");
 }

lib/SILGen/SILGen.h

@@ -523,8 +523,6 @@ class LLVM_LIBRARY_VISIBILITY SILGenModule : public ASTVisitor<SILGenModule> {
   /// Retrieve the conformance of NSError to the Error protocol.
   ProtocolConformance *getNSErrorConformanceToError();
 
-  /// Retrieve the _Concurrency._asyncLetStart intrinsic.
-  FuncDecl *getAsyncLetStart();
   /// Retrieve the _Concurrency._asyncLetGet intrinsic.
   FuncDecl *getAsyncLetGet();
   /// Retrieve the _Concurrency._asyncLetGetThrowing intrinsic.