JS IR: per-module .js generation support

js/js.translator/testData/box/crossModuleRefIR/lambda.kt

@@ -0,0 +1,19 @@
+// SPLIT_PER_MODULE
+// EXPECTED_REACHABLE_NODES: 1283
+// MODULE: lib
+// FILE: lib.kt
+package lib
+
+fun bar(f: () -> String) = f()
+
+inline fun foo(): String {
+    return bar { "OK" }
+}
+
+// MODULE: main(lib)
+// FILE: main.kt
+package main
+
+import lib.*
+
+fun box() = foo()