NI: clean calls in coroutine inference before the second analysis of += only for right side

^KT-39660 Fixed

compiler/testData/codegen/box/inference/plusAssignInsideLambda.kt

@@ -0,0 +1,22 @@
+// WITH_RUNTIME
+
+import kotlin.experimental.ExperimentalTypeInference
+
+interface SendChannel<in T> {
+    suspend fun send(value: T)
+}
+
+@OptIn(ExperimentalTypeInference::class)
+public fun <T> flux(@BuilderInference block: suspend SendChannel<T>.() -> Unit) {}
+
+suspend inline fun <T> T.collect(action: (T) -> Unit) { action(this) }
+
+fun test() {
+    flux {
+        var result = ""
+        "OK".collect { result += it }
+        send(result)
+    }
+}
+
+fun box() = "OK"