JS: don't remove debugger statement from coroutine

See KT-19826

js/js.translator/testData/box/coroutines/debugStatement.kt

@@ -0,0 +1,14 @@
+// EXPECTED_REACHABLE_NODES: 1152
+// CHECK_DEBUGGER_COUNT: function=doResume count=1
+
+fun foo(f: suspend () -> Unit) {
+}
+
+fun box(): String {
+    foo {
+        println("aaa")
+        js("debugger;")
+        println("bbb")
+    }
+    return "OK"
+}