Fix Array.prototype.reduce and reduceRight (#3487)

Don't throw TypeError when object length is 0 and initialValue is undefined.
Additionally the error message should be more precise and match other engines.

Fixes #3463

JerryScript-DCO-1.0-Signed-off-by: Csaba Osztrogonác oszi@inf.u-szeged.hu

tests/jerry/array-prototype-reduce-right.js

@@ -34,14 +34,6 @@ try {
   assert(e instanceof TypeError);
 }
 
-try {
-  var arg2;
-  [].reduceRight(func, arg2);
-  assert(false);
-} catch(e) {
-  assert(e instanceof TypeError);
-}
-
 try {
   var a = new Array();
   a.length = 10;
@@ -54,6 +46,8 @@ try {
 // various checks
 assert([].reduceRight(func, 1) === 1);
 
+assert([].reduceRight(func, undefined) === undefined);
+
 assert([0].reduceRight(func) === 0);
 
 assert([0, 1].reduceRight(func) === 1);

tests/jerry/array-prototype-reduce.js

@@ -39,6 +39,8 @@ catch(e) {
 // various checks
 assert ([].reduce(func, 1) === 1);
 
+assert ([].reduce(func, undefined) === undefined);
+
 assert ([0].reduce(func) === 0);
 
 assert ([0, 1].reduce(func) === 1);