Remove main function from some external tests

backend.native/tests/external/codegen/blackbox/arrays/kt4348.kt

@@ -5,7 +5,7 @@ operator fun String.get(vararg value: Any) : String {
 operator fun Int.get(vararg value: Any) : Int {
     return if (value[0] == 44 && value[1] == "example") 1 else 0
 }
-fun main(args: Array<String>) {
+fun foo(args: Array<String>) {
     12  [44, "example"]
 }
 

backend.native/tests/external/codegen/blackbox/bridges/kt1959.kt

@@ -6,7 +6,7 @@ class B(): A<String>() {
     override fun f(args : Array<String>) {}
 }
 
-fun main(args: Array<String>) {
+fun foo(args: Array<String>) {
     B()
 }
 

backend.native/tests/external/codegen/blackbox/controlStructures/kt2259.kt

@@ -1,4 +1,4 @@
-fun main(args: Array<String>) {
+fun foo(args: Array<String>) {
     try {
     } finally {
         try {

backend.native/tests/external/codegen/blackbox/controlStructures/kt237.kt

@@ -1,7 +1,7 @@
 // TODO: muted automatically, investigate should it be ran for JS or not
 // IGNORE_BACKEND: JS, NATIVE
 
-fun main(args: Array<String>?) {
+fun foo(args: Array<String>?) {
     val y: Unit = Unit //do not compile
     A<Unit>()        //do not compile
     C<Unit>(Unit)      //do not compile
@@ -39,6 +39,6 @@ fun box() : String {
     a[2] = 2
     foreach(a, { el : Int -> System.out?.println(el) })
     almostFilter(a, { el : Int -> el })
-    main(null)
+    foo(null)
     return "OK"
 }

backend.native/tests/external/codegen/blackbox/diagnostics/vararg/kt4172.kt

@@ -1,9 +1,9 @@
 fun box(): String {
-    main(array())
+    foo(array())
     return "OK"
 }
 
-fun main(args: Array<String>) {
+fun foo(args: Array<String>) {
     D.foo(array())
 }