JVM: fix type mapping of big arity suspend function types

The code in IrTypeMapper was incorrectly translated from
KotlinTypeMapper during the development of JVM IR. The
`classDescriptor.hasBigArity` condition in KotlinTypeMapper was checking
if the class represents a function or a suspend function with big arity,
and the suspend function part was lost during conversion.

This resulted in incorrect generic signature being generated, which led
to malformed type exceptions from reflection, and compilation errors
from kapt stub generation.

Also, change a comment in irCodegenUtils to avoid confusion of numbered
function types (kotlin.jvm.functions.Function1, ...) with the big-arity
type kotlin.jvm.functions.FunctionN.

 #KT-58375 Fixed

compiler/testData/codegen/box/coroutines/reflect/bigArityLambda.kt

@@ -0,0 +1,34 @@
+// TARGET_BACKEND: JVM
+// WITH_REFLECT
+// WITH_COROUTINES
+
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+import kotlin.reflect.full.*
+
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+interface Flow<T>
+
+class C
+
+suspend fun foo(
+    f: suspend (C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C) -> String
+): String =
+    f(C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C(), C())
+
+fun box(): String {
+    var res = "Fail"
+    builder {
+        val f: suspend (C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C) -> String = {
+            _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _ ->
+            "OK"
+        }
+        res = ::foo.callSuspend(f)
+    }
+    return res
+}