Eliminate the allocation of spread object (#3333)

ECMA_VALUE_SPREAD_ELEMENT can be used to represent that the next argument needs to be spreaded, therefore no allocation is needed.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

jerry-core/ecma/base/ecma-globals.h

@@ -190,6 +190,8 @@ enum
                                                   *   a special "base" value for vm */
   ECMA_VALUE_IMPLICIT_CONSTRUCTOR = ECMA_MAKE_VALUE (9), /**< special value for bound class constructors */
   ECMA_VALUE_UNINITIALIZED = ECMA_MAKE_VALUE (10), /**< a special value for uninitialized let/const declarations */
+  ECMA_VALUE_SPREAD_ELEMENT = ECMA_MAKE_VALUE (11), /**< a special value for spread elements in array initialization
+                                                     *   or function call argument list */
 };
 
 #if !ENABLED (JERRY_NUMBER_TYPE_FLOAT64)
@@ -630,8 +632,7 @@ typedef enum
   ECMA_PSEUDO_SET_ITERATOR = 4, /**< Set iterator object (ECMAScript v6, 23.2.5.1) */
   ECMA_PSEUDO_MAP_ITERATOR = 5, /**< Map iterator object (ECMAScript v6, 23.1.5.1) */
   ECMA_PSEUDO_STRING_ITERATOR = 6, /**< String iterator object (ECMAScript v6, 22.1.5.1) */
-  ECMA_PSEUDO_SPREAD_OBJECT = 7, /**< spread object */
-  ECMA_PSEUDO_ARRAY__MAX = ECMA_PSEUDO_SPREAD_OBJECT /**< maximum value */
+  ECMA_PSEUDO_ARRAY__MAX = ECMA_PSEUDO_STRING_ITERATOR /**< maximum value */
 } ecma_pseudo_array_type_t;
 
 /**