Revisit unused global functions in jerry-core (#2450)

There are some leftover global functions in the code that are not
referenced at all anymore. These functions are removed by this
patch.

There are also some global functions that are only used in their
own modules. These functions are made static by this patch.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-core/lit/lit-char-helpers.c

@@ -101,20 +101,6 @@ search_char_in_interval_array (ecma_char_t c,               /**< code unit */
   return false;
 } /* search_char_in_interval_array */
 
-/**
- * Check if specified character is one of the Format-Control characters
- *
- * @return true - if the character is one of characters, listed in ECMA-262 v5, Table 1,
- *         false - otherwise
- */
-bool
-lit_char_is_format_control (ecma_char_t c) /**< code unit */
-{
-  return (c == LIT_CHAR_ZWNJ
-          || c == LIT_CHAR_ZWJ
-          || c == LIT_CHAR_BOM);
-} /* lit_char_is_format_control */
-
 /**
  * Check if specified character is one of the Whitespace characters including those
  * that fall into "Space, Separator" ("Zs") Unicode character category.