Generate continuation class for suspend lambdas

generate state-machine for coroutines.

compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/builders/declarations/declarationBuilders.kt

@@ -8,11 +8,14 @@ package org.jetbrains.kotlin.ir.builders.declarations
 import org.jetbrains.kotlin.backend.common.descriptors.*
 import org.jetbrains.kotlin.backend.common.ir.copyTo
 import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.*
 import org.jetbrains.kotlin.ir.symbols.impl.*
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.overrides
 import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.Variance
@@ -58,6 +61,13 @@ inline fun IrDeclarationContainer.addField(b: IrFieldBuilder.() -> Unit) =
         declarations.add(field)
     }
 
+fun IrClass.addField(fieldName: String, fieldType: IrType, fieldVisibility: Visibility = Visibilities.PRIVATE): IrField =
+    addField {
+        name = Name.identifier(fieldName)
+        type = fieldType
+        visibility = fieldVisibility
+    }
+
 fun IrPropertyBuilder.buildProperty(): IrProperty {
     val wrappedDescriptor = WrappedPropertyDescriptor()
     return IrPropertyImpl(
@@ -154,6 +164,12 @@ fun IrDeclarationContainer.addFunction(
         }
     }
 
+fun IrDeclarationContainer.addFunctionOverride(function: IrSimpleFunction, modality: Modality = Modality.FINAL): IrSimpleFunction =
+    addFunction(function.name.asString(), function.returnType, modality).apply {
+        overriddenSymbols.add(function.symbol)
+        valueParameters.addAll(function.valueParameters.map { it.copyTo(this) })
+    }
+
 inline fun buildConstructor(b: IrFunctionBuilder.() -> Unit): IrConstructor =
     IrFunctionBuilder().run {
         b()