Delete unused NoOp instruction (#3586)

toolchain/check/context.cpp

@@ -953,7 +953,6 @@ class TypeCompleter {
       case SemIR::LazyImportRef::Kind:
       case SemIR::NameRef::Kind:
       case SemIR::Namespace::Kind:
-      case SemIR::NoOp::Kind:
       case SemIR::Param::Kind:
       case SemIR::RealLiteral::Kind:
       case SemIR::Return::Kind:

toolchain/lower/handle.cpp

@@ -242,11 +242,6 @@ auto HandleNamespace(FunctionContext& /*context*/, SemIR::InstId /*inst_id*/,
   FatalErrorIfEncountered(inst);
 }
 
-auto HandleNoOp(FunctionContext& /*context*/, SemIR::InstId /*inst_id*/,
-                SemIR::NoOp /*inst*/) -> void {
-  // No action to take.
-}
-
 auto HandleParam(FunctionContext& /*context*/, SemIR::InstId /*inst_id*/,
                  SemIR::Param /*inst*/) -> void {
   CARBON_FATAL() << "Parameters should be lowered by `BuildFunctionDefinition`";

toolchain/sem_ir/file.cpp

@@ -226,7 +226,6 @@ static auto GetTypePrecedence(InstKind kind) -> int {
     case IntLiteral::Kind:
     case LazyImportRef::Kind:
     case Namespace::Kind:
-    case NoOp::Kind:
     case Param::Kind:
     case RealLiteral::Kind:
     case Return::Kind:
@@ -433,7 +432,6 @@ auto File::StringifyTypeExpr(InstId outer_inst_id) const -> std::string {
       case IntLiteral::Kind:
       case LazyImportRef::Kind:
       case Namespace::Kind:
-      case NoOp::Kind:
       case Param::Kind:
       case RealLiteral::Kind:
       case Return::Kind:
@@ -490,7 +488,6 @@ auto GetExprCategory(const File& file, InstId inst_id) -> ExprCategory {
       case InterfaceDecl::Kind:
       case LazyImportRef::Kind:
       case Namespace::Kind:
-      case NoOp::Kind:
       case Return::Kind:
       case ReturnExpr::Kind:
       case StructTypeField::Kind:

toolchain/sem_ir/inst_kind.def

@@ -52,7 +52,6 @@ CARBON_SEM_IR_INST_KIND(IntLiteral)
 CARBON_SEM_IR_INST_KIND(LazyImportRef)
 CARBON_SEM_IR_INST_KIND(NameRef)
 CARBON_SEM_IR_INST_KIND(Namespace)
-CARBON_SEM_IR_INST_KIND(NoOp)
 CARBON_SEM_IR_INST_KIND(Param)
 CARBON_SEM_IR_INST_KIND(PointerType)
 CARBON_SEM_IR_INST_KIND(RealLiteral)

toolchain/sem_ir/typed_insts.h

@@ -453,14 +453,6 @@ struct Namespace {
   NameScopeId name_scope_id;
 };
 
-struct NoOp {
-  static constexpr auto Kind = InstKind::NoOp.Define("no_op");
-
-  // TODO: Delete since now unused.
-  Parse::NodeId parse_node;
-  // This instruction doesn't produce a value, so has no type.
-};
-
 struct Param {
   static constexpr auto Kind = InstKind::Param.Define("param");