Support @CName annotation for reverse C interop, similar to @JvmName. (#1237)

backend.native/tests/produce_dynamic/simple/main.c

@@ -18,7 +18,6 @@ int main(void) {
 
     const char* string = __ kotlin.root.getString();
 
-
     __ kotlin.root.hello();
     __ kotlin.root.Base.foo(base);
     __ kotlin.root.Base.fooParam(base, "a", 1);
@@ -37,6 +36,10 @@ int main(void) {
 
     printf("object = %d\n",  __ kotlin.root.Codeable.asCode(object1));
 
+    topLevelFunctionVoidFromC(42);
+    __ kotlin.root.topLevelFunctionVoid(42);
+    printf("topLevel = %d %d\n", topLevelFunctionFromC(780, 3), __ kotlin.root.topLevelFunctionFromCShort(5, 2));
+
     __ DisposeString(string);
     __ DisposeStablePointer(base.pinned);
     __ DisposeStablePointer(child.pinned);