Copy location info when copying JS AST subtrees

This is necessary to preserve source information of a function's body
after inlining.

js/js.translator/testData/lineNumbers/inlining.kt

@@ -0,0 +1,14 @@
+fun box() {
+    println("1")
+    bar()
+    println("2")
+    bar()
+    println("3")
+}
+
+inline fun bar() {
+    println("bar1")
+    println("bar2")
+}
+
+// LINES: 2 10 11 4 10 11 6 10 11