[FIR JS] Prepare the test data for FIR

compiler/testData/diagnostics/testsWithJsStdLib/jsCode/noJavaScriptProduced.fir.kt

@@ -0,0 +1,16 @@
+fun test() {
+    js("")
+    js(" ")
+    js("""
+               """)
+
+    val empty = ""
+    js(empty)
+
+    val whitespace = "  "
+    js(whitespace)
+
+    val multiline = """
+    """
+    js(multiline)
+}