combined two files and modified file name

Author: G-Lee1031

test/built-ins/BigInt/prototype/toString/radix-tointegerorinfinity-throws-bigint.js

@@ -4,7 +4,7 @@
 /*---
 esid: sec-bigint.prototype.tostring
 description: > 
-    ToNumber called by BigInt.prototype.toString throws when ToPrimitive Throws
+    ToNumber called by BigInt.prototype.toString throws when _radix_ is a BigInt or when ToPrimitive Throws
 info: |
     BigInt.prototype.toString ( [ _radix_ ] )
 
@@ -16,10 +16,18 @@ info: |
 
     ToNumber (_argument_)
 
+    2. If _argument_ is either a Symbol or a BigInt, throw a *TypeError* exception.
+
     7. Assert: _argument_ is an Object.
     8. Let _primValue_ be ? ToPrimitive(_argument_, ~number~).
 features: [BigInt]
 ---*/
+//Check #1
+assert.throws(TypeError, function() {
+    (0n).toString(0n);
+}, "If _radix_ is BigInt, BigInt.prototype.toString must throw a TypeError")
+
+//Check #2
 assert.throws(TypeError, function() {
     BigInt.prototype.toString.call(10n, {valueOf: undefined, toString: undefined})
 }, "TypeError is thrown when _radix_ cannot be converted to a primitive")