Fixes for KT-4991: Prefix/postfix expressions resolved to local extensions are not supported in codegen;

KT-4989: Verify error on local functions and extensions;
KT-4987: NegativeArraySizeException on local extension convention function on nullable Int

  #KT-4991 Fixed
  #KT-4989 Fixed
  #KT-4987 Fixed

compiler/testData/codegen/box/functions/localFunctions/kt4989.kt

@@ -0,0 +1,24 @@
+class It(val id: String)
+
+fun box(): String {
+    val projectId = "projectId"
+    val it = It("it")
+
+
+    fun selectMetaRunnerId(): String {
+        fun Int?.inc() = (this ?: 0) + 1
+        var counter: Int? = null
+        fun path(metaRunnerId: String) = counter != 2
+
+        while (true) {
+            val name = projectId + "_" + it.id + (if (counter == null) "" else "_$counter")
+            if (!path(name)) {
+                return name
+            }
+            counter++
+        }
+    }
+    val X = selectMetaRunnerId()
+    if (X != projectId + "_" + it.id + "_2") return "fail: $X"
+    return "OK"
+}