[NI] Fix exception: don't try to compute type depth on null type

#KT-32184 Fixed

compiler/testData/diagnostics/tests/functionLiterals/functionLiteralAsArgumentForFunction.kt

@@ -0,0 +1,25 @@
+class Log
+
+data class CalculatedVariable(
+    val idString: String,
+    val presentableName: String,
+    val units: String,
+    val function: (Log) -> ((TimeIndex) -> Any?)?,
+    val converter: (Any) -> Double
+) {
+    constructor(idString: String, presentableName: String, units: String, function: (Log) -> ((TimeIndex) -> Double?)?)
+            : this(idString, presentableName, units, function, { it as Double })
+}
+
+object CalculatedVariables {
+    val x = CalculatedVariable(
+        "A",
+        "B",
+        "C",
+        fun(<!UNUSED_ANONYMOUS_PARAMETER!>log<!>: Log): ((TimeIndex) -> Double?)? {
+            return { 0.0 }
+        }
+    )
+}
+
+class TimeIndex