IR: default parameter extension support

for code
```
fun Int.foo(a:Int, b:Int = a + 1, c:Int = a + b) = a + b +c

fun main(arg:Array<String>) {
  42.foo(0)
}
```
we generate IR representation corresponding to the following code
```
fun Int.foo(a:Int, b:Int, c:Int) = a + b +c

fun foo_default(a:Int, b:Int, c:Int, __mask__:Int, __receiver__:Int):Int {
    var tmpb:Int = 0
    if ((__mask__ and (1 shl 1)) != 0)
        tmpb = a + 1
    else
        tmpb = b
    var tmpc:Int = 0
    if ((__mask__ and (1 shl 2)) != 0)
        tmpc = a + tmpb
    else
        tmpc = c
    return __receiver__.foo(a, tmpb, tmpc)
}

fun main(arg:Array<String>) {
  foo_default(0, 0, 0, 6 /* (1 shl 1) | (1 shl 2)*/, 42)
}
```

NOTE: if call provides all arguents we don't emit call of _default function.

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

@@ -51,7 +51,7 @@ internal class KonanLower(val context: Context) {
             Autoboxing(context).lower(irFile)
         }
         phaser.phase(KonanPhase.LOWER_INLINE) {
-            //FunctionInlining(context).inline(irFile)
+            FunctionInlining(context).inline(irFile)
         }
     }
 }