Fix source mapping for stepping into package facades from libraries (KT-28028)

idea/testData/debugger/tinyApp/src/stepping/stepInto/sameFileNames.kt

@@ -0,0 +1,8 @@
+package sameFileNames
+
+fun main() {
+    //Breakpoint!
+    val result = simple.foo()
+}
+
+// STEP_INTO: 1

idea/testData/debugger/tinyApp/src/stepping/stepInto/sameFileNames.out

@@ -0,0 +1,8 @@
+LineBreakpoint created at sameFileNames.kt:5
+Run Java
+Connected to the target VM
+sameFileNames.kt:5
+simpleKt.kt:5
+Disconnected from the target VM
+
+Process finished with exit code 0