Generate return when generating continuation class for expression body

Otherwise, the function will return Unit instead of correct value.
 #KT-46007 Fixed

compiler/testData/codegen/box/coroutines/featureIntersection/jvmDefault/kt46007/all-compatibility.kt

@@ -0,0 +1,30 @@
+// WITH_RUNTIME
+// !JVM_DEFAULT_MODE: all-compatibility
+// TARGET_BACKEND: JVM
+// IGNORE_LIGHT_ANALYSIS
+// IGNORE_BACKEND: JVM
+// JVM_TARGET: 1.8
+
+import kotlin.coroutines.*
+
+class A : BlockingDoubleChain
+
+interface BlockingDoubleChain : BlockingBufferChain
+
+interface BlockingBufferChain {
+    suspend fun nextBuffer(): String = "OK"
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(Continuation(EmptyCoroutineContext) {
+        it.getOrThrow()
+    })
+}
+
+fun box(): String {
+    var res = "FAIL"
+    builder {
+        res = A().nextBuffer()
+    }
+    return res
+}

compiler/testData/codegen/box/coroutines/featureIntersection/jvmDefault/kt46007/all.kt

@@ -0,0 +1,28 @@
+// WITH_RUNTIME
+// !JVM_DEFAULT_MODE: all
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+
+import kotlin.coroutines.*
+
+class A : BlockingDoubleChain
+
+interface BlockingDoubleChain : BlockingBufferChain
+
+interface BlockingBufferChain {
+    suspend fun nextBuffer(): String = "OK"
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(Continuation(EmptyCoroutineContext) {
+        it.getOrThrow()
+    })
+}
+
+fun box(): String {
+    var res = "FAIL"
+    builder {
+        res = A().nextBuffer()
+    }
+    return res
+}

compiler/testData/codegen/box/coroutines/featureIntersection/jvmDefault/kt46007/disable.kt

@@ -0,0 +1,28 @@
+// WITH_RUNTIME
+// !JVM_DEFAULT_MODE: disable
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+
+import kotlin.coroutines.*
+
+class A : BlockingDoubleChain
+
+interface BlockingDoubleChain : BlockingBufferChain
+
+interface BlockingBufferChain {
+    suspend fun nextBuffer(): String = "OK"
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(Continuation(EmptyCoroutineContext) {
+        it.getOrThrow()
+    })
+}
+
+fun box(): String {
+    var res = "FAIL"
+    builder {
+        res = A().nextBuffer()
+    }
+    return res
+}

compiler/testData/codegen/box/coroutines/featureIntersection/jvmDefault/kt46007/enable.kt

@@ -0,0 +1,28 @@
+// WITH_RUNTIME
+// !JVM_DEFAULT_MODE: enable
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+
+import kotlin.coroutines.*
+
+class A : BlockingDoubleChain
+
+interface BlockingDoubleChain : BlockingBufferChain
+
+interface BlockingBufferChain {
+    suspend fun nextBuffer(): String = "OK"
+}
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(Continuation(EmptyCoroutineContext) {
+        it.getOrThrow()
+    })
+}
+
+fun box(): String {
+    var res = "FAIL"
+    builder {
+        res = A().nextBuffer()
+    }
+    return res
+}