Scanner rework. (#3038)

The scanner was an on-demand tool of the parser, which was triggered by certain
statements. After the rework, the scanner runs only once, and collects all information.
This information is passed to the parser.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/parser/js/js-lexer.h

@@ -255,6 +255,16 @@ typedef enum
   LEXER_OBJ_IDENT_CLASS_METHOD = (1u << 2),     /**< expect identifier inside a class body */
 } lexer_obj_ident_opts_t;
 
+/**
+ * Lexer scan identifier parse options.
+ */
+typedef enum
+{
+  LEXER_SCAN_IDENT_NO_OPTS = (1u << 0),          /**< no options */
+  LEXER_SCAN_IDENT_PROPERTY = (1u << 1),         /**< scan valid property names */
+  LEXER_SCAN_IDENT_NO_KEYW = (1u << 2),          /**< don\t scan keywords (e.g. get/set) */
+} lexer_scan_ident_opts_t;
+
 /**
  * Lexer literal object types.
  */