dynamic receiver admits nullable values

compiler/testData/diagnostics/tests/dynamicTypes/block.kt

@@ -0,0 +1,16 @@
+// !MARK_DYNAMIC_CALLS
+
+// MODULE[js]: m1
+// FILE: k.kt
+
+fun foo() {
+    dynamic {
+        <!DEBUG_INFO_DYNAMIC!>foo<!>()
+        <!DEBUG_INFO_DYNAMIC!>bar<!>.<!DEBUG_INFO_DYNAMIC!>baz<!>(0)
+    }
+}
+
+fun dynamic<T>(body: dynamic.() -> T): T {
+    val topLevel = null
+    return topLevel.body()
+}

compiler/testData/diagnostics/tests/dynamicTypes/block.txt

@@ -0,0 +1,4 @@
+package
+
+internal fun </*0*/ T> dynamic(/*0*/ body: dynamic.() -> T): T
+internal fun foo(): kotlin.Unit