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.

test/break/nested_for_loop.wren

@@ -1,9 +1,9 @@
 for (i in 0..2) {
-  IO.print("outer " + i.toString)
+  IO.print("outer ", i)
   if (i > 1) break
 
   for (j in 0..2) {
-    IO.print("inner " + j.toString)
+    IO.print("inner ", j)
     if (j > 1) break
   }
 }

test/break/nested_while_loop.wren

@@ -1,11 +1,11 @@
 var i = 0
 while (true) {
-  IO.print("outer " + i.toString)
+  IO.print("outer ", i)
   if (i > 1) break
 
   var j = 0
   while (true) {
-    IO.print("inner " + j.toString)
+    IO.print("inner ", j)
     if (j > 1) break
 
     j = j + 1

test/class/name_inside_body.wren

@@ -1,10 +1,10 @@
 class Foo {
   static sayName {
-    IO.print(Foo.toString)
+    IO.print(Foo)
   }
 
   sayName {
-    IO.print(Foo.toString)
+    IO.print(Foo)
   }
 
   static toString { "Foo!" }

test/constructor/superclass.wren

@@ -1,6 +1,6 @@
 class A {
   new(arg) {
-    IO.print("new A " + arg)
+    IO.print("new A ", arg)
     _field = arg
   }
 
@@ -10,7 +10,7 @@ class A {
 class B is A {
   new(arg1, arg2) {
     super(arg2)
-    IO.print("new B " + arg1)
+    IO.print("new B ", arg1)
     _field = arg1
   }
 

test/function/call_extra_arguments.wren

@@ -1,7 +1,7 @@
 var f0 = new Fn { IO.print("zero") }
-var f1 = new Fn {|a| IO.print("one " + a) }
-var f2 = new Fn {|a, b| IO.print("two " + a + " " + b) }
-var f3 = new Fn {|a, b, c| IO.print("three " + a + " " + b + " " + c) }
+var f1 = new Fn {|a| IO.print("one ", a) }
+var f2 = new Fn {|a, b| IO.print("two ", a, " ", b) }
+var f3 = new Fn {|a, b, c| IO.print("three ", a, " ", b, " ", c) }
 
 f0.call("a") // expect: zero
 f0.call("a", "b") // expect: zero

test/function/call_missing_arguments.wren

@@ -1,2 +1,2 @@
-var f2 = new Fn {|a, b| IO.print(a + b) }
+var f2 = new Fn {|a, b| IO.print(a, b) }
 f2.call("a") // expect runtime error: Function expects more arguments.

test/io/print.wren

@@ -0,0 +1,25 @@
+// With one argument, returns the argument.
+IO.print(IO.print(1) == 1) // expect: 1
+                           // expect: true
+
+// With more than one argument, returns null.
+IO.print(IO.print(1, 2) == null) // expect: 12
+                                 // expect: true
+
+// Allows multiple arguments and concatenates them.
+IO.print(1) // expect: 1
+IO.print(1, 2) // expect: 12
+IO.print(1, 2, 3) // expect: 123
+IO.print(1, 2, 3, 4) // expect: 1234
+IO.print(1, 2, 3, 4, 5) // expect: 12345
+IO.print(1, 2, 3, 4, 5, 6) // expect: 123456
+IO.print(1, 2, 3, 4, 5, 6, 7) // expect: 1234567
+IO.print(1, 2, 3, 4, 5, 6, 7, 8) // expect: 12345678
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9) // expect: 123456789
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) // expect: 12345678910
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) // expect: 1234567891011
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) // expect: 123456789101112
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13) // expect: 12345678910111213
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14) // expect: 1234567891011121314
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15) // expect: 123456789101112131415
+IO.print(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16) // expect: 12345678910111213141516