Debugger: Fix step over in functions with default parameters (KT-14828)

Adds a synthetic line number just before the original function call.
The new line number is recognized by the debugger which replaces the
  'step over' action with 'step into' and stops.

idea/jvm-debugger/jvm-debugger-test/testData/stepping/custom/afterDefaultParameterValues2Intf.kt

@@ -0,0 +1,26 @@
+package test
+
+fun main() {
+    val foo = FooImpl()
+    //Breakpoint!
+    foo.call()
+    foo.foo()
+}
+
+interface Foo {
+    fun call(a: Int = def()) {
+        foo()
+    }
+
+    fun def(): Int {
+        return libFun() // 'Step over' causes debugger skipping call()
+    }
+
+    fun foo() {}
+    fun libFun() = 12
+}
+
+class FooImpl : Foo
+
+// STEP_INTO: 2
+// STEP_OVER: 7