'SuspendFunction$n' should not be visible in member scopes (should be unresolved).

'SuspendFunction$n' class descriptors are created on demand by KotlinBuiltIns (and cached).
On serialization, types constructed with 'SuspendFunction$n' are written as 'Function$n' with extra flag (SUSPEND_TYPE).
On deserialization, corresponding 'SuspendFunction$n' classes are used.

idea/testData/decompiler/decompiledText/TypeModifiers.expected.kt

@@ -0,0 +1,15 @@
+// IntelliJ API Decompiler stub source generated from a class file
+// Implementation of methods is not available
+
+package test
+
+public final class TypeModifiers public constructor() {
+    public final val function: () -> kotlin.Unit /* compiled code */
+
+    public final val functionOnSuspendFunction: (suspend () -> kotlin.Unit).() -> kotlin.Unit /* compiled code */
+
+    public final val suspendExtFunction: suspend kotlin.Any.() -> kotlin.Unit /* compiled code */
+
+    public final val suspendFunction: suspend () -> kotlin.Unit /* compiled code */
+}
+

idea/testData/decompiler/decompiledText/TypeModifiers/TypeModifiers.kt

@@ -0,0 +1,11 @@
+package test
+
+class TypeModifiers {
+    val function: () -> Unit = null!!
+
+    val suspendFunction: suspend () -> Unit = null!!
+
+    val suspendExtFunction: suspend Any.() -> Unit = null!!
+
+    val functionOnSuspendFunction: (suspend () -> Unit).() -> Unit = null!!
+}