Suppot inlining default methods, inlining function into its default.

compiler/testData/codegen/boxInline/simpleDefaultMethod/1.kt

@@ -0,0 +1,22 @@
+import test.*
+
+fun testCompilation(): String {
+    emptyFun()
+    emptyFun("K")
+
+    return "OK"
+}
+
+fun simple(): String {
+    return simpleFun() + simpleFun("K")
+}
+
+fun box(): String {
+    var result = testCompilation()
+    if (result != "OK") return "fail1: ${result}"
+
+    result = simple()
+    if (result != "OK") return "fail2: ${result}"
+
+    return "OK"
+}

compiler/testData/codegen/boxInline/simpleDefaultMethod/2.kt

@@ -0,0 +1,11 @@
+package test
+
+inline fun emptyFun(arg: String = "O") {
+
+}
+
+inline fun simpleFun(arg: String = "O"): String {
+    val r = arg;
+    return r;
+}
+