feat: add overloaded IO.print methods accepting 2-16 arguments and printList_ helper

Add 15 static overloads of IO.print in builtin/io.wren and src/wren_io.c, each delegating to a new private printList_ method that iterates over a list of objects. Update all benchmark and test files to use the new multi-argument syntax, removing explicit .toString calls and string concatenation. Add a comprehensive test/io/print.wren verifying single-argument return value, multi-argument null return, and concatenation of up to 16 arguments.

benchmark/binary_trees.wren

@@ -26,8 +26,8 @@ var stretchDepth = maxDepth + 1
 
 var start = IO.clock
 
-IO.print("stretch tree of depth " + stretchDepth.toString + " check: " +
-    new Tree(0, stretchDepth).check.toString)
+IO.print("stretch tree of depth ", stretchDepth, " check: ",
+    new Tree(0, stretchDepth).check)
 
 var longLivedTree = new Tree(0, maxDepth)
 
@@ -44,13 +44,10 @@ while (depth < stretchDepth) {
     check = check + new Tree(i, depth).check + new Tree(-i, depth).check
   }
 
-  IO.print((iterations * 2).toString + " trees of depth " + depth.toString +
-      " check: " + check.toString)
+  IO.print((iterations * 2), " trees of depth ", depth, " check: ", check)
   iterations = iterations / 4
   depth = depth + 2
 }
 
-IO.print("long lived tree of depth " + maxDepth.toString + " check: " +
-    longLivedTree.check.toString)
-
-IO.print("elapsed: " + (IO.clock - start).toString)
+IO.print("long lived tree of depth ", maxDepth, " check: ", longLivedTree.check)
+IO.print("elapsed: ", (IO.clock - start))

benchmark/delta_blue.wren

@@ -713,5 +713,5 @@ for (i in 0...20) {
 }
 
 IO.print(total)
-IO.print("elapsed: " + (IO.clock - start).toString)
+IO.print("elapsed: ", IO.clock - start)
 

benchmark/fib.wren

@@ -7,4 +7,4 @@ var start = IO.clock
 for (i in 1..5) {
   IO.print(fib.call(28))
 }
-IO.print("elapsed: " + (IO.clock - start).toString)
+IO.print("elapsed: ", IO.clock - start)

benchmark/for.wren

@@ -7,4 +7,4 @@ var sum = 0
 for (i in list) sum = sum + i
 
 IO.print(sum)
-IO.print("elapsed: " + (IO.clock - start).toString)
+IO.print("elapsed: ", IO.clock - start)

benchmark/method_call.wren

@@ -65,5 +65,4 @@ for (i in 0...n) {
 }
 
 IO.print(ntoggle.value)
-
-IO.print("elapsed: " + (IO.clock - start).toString)
+IO.print("elapsed: ", IO.clock - start)