Warning fixes.

ISO C99 doesn’t support unnamed structs/unions.
Comparison of distinct pointer types lacks a cast.
Dereferencing type-punned pointer will break strict-aliasing rules.
Type of bit-field ‘ext’ is a GCC extension.

JerryScript-DCO-1.0-Signed-off-by: Robert Sipka rsipka.uszeged@partner.samsung.com

jerry-core/lit/lit-strings.h

@@ -99,7 +99,7 @@
  */
 typedef struct
 {
-  lit_utf8_size_t offset : LIT_ITERATOR_OFFSET_WIDTH; /** offset to utf-8 char */
+  __extension__ lit_utf8_size_t offset : LIT_ITERATOR_OFFSET_WIDTH; /** offset to utf-8 char */
   bool is_non_bmp_middle: 1; /** flag indicating that current position of the iterator is the middle of
                               *  4-byte char */
 } lit_utf8_iterator_pos_t;