Remove the hack to fix percentage signs in Node.js.

Back when that hack was introduced in
1fc8d0526ba9b46049c0deefc3fe3fa93d3271b0, Node.js' `console.log`
deduplicated consecutive `%` signs in its argument, even if it was
a single argument. At the time we thought that was intentional, and
we added our hack to have it behave in a more standard way for
Scala.js.

The deduplication with only 1 argument turned out to be a bug,
recognized as such in nodejs/node#3396,
when it was accidentally fixed in Node.js 4. It is now the
documented behavior, see
https://nodejs.org/api/util.html#util_util_format_format_args
which is referenced from
https://nodejs.org/api/console.html#console_console_log_data_args.

Author: sjrd

js-envs-test-kit/src/main/scala/org/scalajs/jsenv/test/RunTests.scala

@@ -95,50 +95,19 @@ private[test] class RunTests(config: JSEnvSuiteConfig, withCom: Boolean) {
     }
   }
 
-  @Test // Node.js strips double percentage signs - #500
+  // #500 Node.js used to strip double percentage signs even with only 1 argument
+  @Test
   def percentageTest: Unit = {
-    val counts = 1 to 15
-    val argcs  = 1 to 3
-    val strings = counts.map("%" * _)
-
-    val strlists = for {
-      count  <- argcs
-      string <- strings
-    } yield List.fill(count)(string)
-
-    val codes = for {
-      strlist <- strlists
-    } yield {
-      val args = strlist.map(s => s""""$s"""").mkString(", ")
-      s"console.log($args);\n"
-    }
+    val strings = (1 to 15).map("%" * _)
+    val code = strings.map(str => s"""console.log("$str");\n""").mkString("")
+    val result = strings.mkString("", "\n", "\n")
 
-    val result = strlists.map(_.mkString(" ") + "\n").mkString("")
-
-    withRun(codes.mkString("")) {
+    withRun(code) {
       _.expectOut(result)
         .closeRun()
     }
   }
 
-  @Test // Node.js console.log hack didn't allow to log non-Strings - #561
-  def nonStringTest: Unit = {
-    withRun("""
-      console.log(1);
-      console.log(undefined);
-      console.log(null);
-      console.log({});
-      console.log([1,2]);
-      """) {
-      _.expectOut("1\n")
-        .expectOut("undefined\n")
-        .expectOut("null\n")
-        .expectOut("[object Object]\n")
-        .expectOut("1,2\n")
-        .closeRun()
-    }
-  }
-
   @Test
   def fastCloseTest: Unit = {
     /* This test also tests a failure mode where the ExternalJSRun is still

nodejs-env/src/main/scala/org/scalajs/jsenv/nodejs/NodeJSEnv.scala

@@ -68,7 +68,7 @@ final class NodeJSEnv(config: NodeJSEnv.Config) extends JSEnv {
   }
 
   private def initFiles: List[VirtualBinaryFile] = {
-    val base = List(NodeJSEnv.runtimeEnv, Support.fixPercentConsole)
+    val base = List(NodeJSEnv.runtimeEnv)
 
     config.sourceMap match {
       case SourceMap.Disable           => base