Eliminated mangled name resolution for Kotlin_start.

Made Kotlin_start private in order to not pollute
the namespace of the default package.

runtime/src/launcher/cpp/launcher.cpp

@@ -15,18 +15,14 @@ ArrayHeader* setupArgs(int argc, char** argv) {
     return args;
 }
 
-#ifdef __linux__
+extern "C" void Kotlin_start(ArrayHeader* );
-extern "C" void konanStart(void*) asm("kfun:start(Array<String>)");
-#else
-extern "C" void konanStart(void*) asm("_kfun:start(Array<String>)");
-#endif
 
 int main(int argc, char** argv) {
 
     InitMemory();
 
     ArrayHeader* args = setupArgs(argc, argv);
-    konanStart(args);
+    Kotlin_start(args);
 
     // Yes, we have to follow Java convention and return zero.
     return 0;

runtime/src/launcher/kotlin/konan/start.kt

@@ -1,7 +1,9 @@
+import konan.internal.ExportForCppRuntime
 
 external fun main(args: Array<String>)
 
-fun start(args: Array<String>) {
+@ExportForCppRuntime
+private fun Kotlin_start(args: Array<String>) {
     try {
 
         // This is kotlin program main entry point