Made bridge methods public.

Added test on usage of a bridge method from different module.
Bridge methods must be public in order use them from other modules.

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Context.kt

@@ -93,7 +93,7 @@ internal class SpecialDescriptorsFactory(val context: Context) {
                 },
                 returnType,
                 descriptor.modality,
-                Visibilities.PRIVATE)
+                Visibilities.PUBLIC)
     }
 }
 

backend.native/tests/build.gradle

@@ -573,6 +573,12 @@ task bridges_test16(type: RunKonanTest) {
     source = "codegen/bridges/test16.kt"
 }
 
+task bridges_linkTest(type: LinkKonanTest) {
+    goldValue = "42\n42\n42\n"
+    source = "codegen/bridges/linkTest_main.kt"
+    lib = "codegen/bridges/linkTest_lib.kt"
+}
+
 task classDelegation_method(type: RunKonanTest) {
     goldValue = "OKOK\n"
     source = "codegen/classDelegation/method.kt"

backend.native/tests/codegen/bridges/linkTest_lib.kt

@@ -0,0 +1,9 @@
+package a
+
+interface A<T> {
+    fun foo(): T
+}
+
+open class C: A<Int> {
+    override fun foo(): Int = 42
+}

backend.native/tests/codegen/bridges/linkTest_main.kt

@@ -0,0 +1,12 @@
+import a.*
+
+class B: C()
+
+fun main(args: Array<String>) {
+    val b = B()
+    println(b.foo())
+    val c: C = b
+    println(c.foo())
+    val a: A<Int> = b
+    println(a.foo())
+}