JVM_IR: Do not generate null checks for suspend function views.

The arguments are null whenever the suspend function is resumed
and takes its state from the continuation parameter.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/DeclarationOrigins.kt

@@ -44,5 +44,6 @@ interface JvmLoweredDeclarationOrigin : IrDeclarationOrigin {
     object INLINE_CLASS_GENERATED_IMPL_METHOD : IrDeclarationOriginImpl("INLINE_CLASS_GENERATED_IMPL_METHOD")
     object GENERATED_ASSERTION_ENABLED_FIELD : IrDeclarationOriginImpl("GENERATED_ASSERTION_ENABLED_FIELD", isSynthetic = true)
     object GENERATED_MAIN_FOR_PARAMETERLESS_MAIN_METHOD : IrDeclarationOriginImpl("GENERATED_MAIN_FOR_PARAMETERLESS_MAIN_METHOD", isSynthetic = true)
+    object SUSPEND_FUNCTION_VIEW : IrDeclarationOriginImpl("SUSPEND_FUNCTION_VIEW")
     object SUSPEND_IMPL_STATIC_FUNCTION :  IrDeclarationOriginImpl("SUSPEND_IMPL_STATIC_FUNCTION", isSynthetic = true)
 }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/CoroutineCodegen.kt

@@ -125,12 +125,10 @@ internal fun IrFunction.shouldNotContainSuspendMarkers(context: JvmBackendContex
 // Transform `suspend fun foo(params): RetType` into `fun foo(params, $completion: Continuation<RetType>): Any?`
 // the result is called 'view', just to be consistent with old backend.
 internal fun IrFunction.getOrCreateSuspendFunctionViewIfNeeded(context: JvmBackendContext): IrFunction {
-    if (!isSuspend || origin == SUSPEND_FUNCTION_VIEW) return this
+    if (!isSuspend || origin == JvmLoweredDeclarationOrigin.SUSPEND_FUNCTION_VIEW) return this
     return if (isSuspend) context.suspendFunctionViews.getOrElse(this) { suspendFunctionView(context) } else this
 }
 
-private object SUSPEND_FUNCTION_VIEW : IrDeclarationOriginImpl("SUSPEND_FUNCTION_VIEW")
-
 private fun IrFunction.suspendFunctionView(context: JvmBackendContext): IrFunction {
     require(this.isSuspend && this is IrSimpleFunction)
     val originalDescriptor = this.descriptor
@@ -146,7 +144,7 @@ private fun IrFunction.suspendFunctionView(context: JvmBackendContext): IrFuncti
         else
             WrappedSimpleFunctionDescriptor(sourceElement = originalDescriptor.source)
     return IrFunctionImpl(
-        startOffset, endOffset, SUSPEND_FUNCTION_VIEW, IrSimpleFunctionSymbolImpl(descriptor),
+        startOffset, endOffset, JvmLoweredDeclarationOrigin.SUSPEND_FUNCTION_VIEW, IrSimpleFunctionSymbolImpl(descriptor),
         name, visibility, modality, context.irBuiltIns.anyNType,
         isInline = isInline, isExternal = isExternal, isTailrec = isTailrec, isSuspend = isSuspend, isExpect = isExpect
     ).also {

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -220,10 +220,19 @@ class ExpressionCodegen(
                 irFunction.origin == JvmLoweredDeclarationOrigin.DEFAULT_IMPLS_BRIDGE ||
                 irFunction.origin == JvmLoweredDeclarationOrigin.JVM_STATIC_WRAPPER ||
                 irFunction.origin == JvmLoweredDeclarationOrigin.MULTIFILE_BRIDGE
-        if (!notCallableFromJava) {
-            irFunction.extensionReceiverParameter?.let { generateNonNullAssertion(it) }
-            irFunction.valueParameters.forEach(::generateNonNullAssertion)
-        }
+
+        if (notCallableFromJava)
+            return
+
+        // Do not generate non-null checks for suspend function views. When resumed the arguments
+        // will be null and the actual values are taken from the continuation.
+        val isSuspendFunctionView = irFunction.origin == JvmLoweredDeclarationOrigin.SUSPEND_FUNCTION_VIEW
+
+        if (isSuspendFunctionView)
+            return
+
+        irFunction.extensionReceiverParameter?.let { generateNonNullAssertion(it) }
+        irFunction.valueParameters.forEach(::generateNonNullAssertion)
     }
 
     private fun generateNonNullAssertion(param: IrValueParameter) {

compiler/testData/codegen/box/coroutines/localFunctions/named/rec.kt

@@ -1,7 +1,6 @@
 // WITH_RUNTIME
 // WITH_COROUTINES
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND: JVM_IR
 
 import helpers.*
 import kotlin.coroutines.*