Fix compile warnings about always_inline functions in GCC 5.2.0

The warning is "always_inline function might not be inlinable", fixed by
adding inline keyword. See:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55830

JerryScript-DCO-1.0-Signed-off-by: Geoff Gustafson geoff@linux.intel.com

jerry-core/lit/lit-cpointer.c

@@ -22,7 +22,7 @@
  *
  * @return dynamic storage-specific extended compressed pointer
  */
-lit_cpointer_t __attr_pure___ __attr_always_inline___
+inline lit_cpointer_t __attr_pure___ __attr_always_inline___
 lit_cpointer_compress (lit_record_t *pointer) /**< pointer to compress */
 {
   if (pointer == NULL)
@@ -38,7 +38,7 @@ lit_cpointer_compress (lit_record_t *pointer) /**< pointer to compress */
  *
  * @return decompressed pointer
  */
-lit_record_t * __attr_pure___ __attr_always_inline___
+inline lit_record_t * __attr_pure___ __attr_always_inline___
 lit_cpointer_decompress (lit_cpointer_t compressed_pointer) /**< recordset-specific compressed pointer */
 {
   if (compressed_pointer == MEM_CP_NULL)
@@ -54,7 +54,7 @@ lit_cpointer_decompress (lit_cpointer_t compressed_pointer) /**< recordset-speci
  *
  * @return NULL compressed pointer
  */
-lit_cpointer_t __attr_pure___ __attr_always_inline___
+inline lit_cpointer_t __attr_pure___ __attr_always_inline___
 lit_cpointer_null_cp (void)
 {
   return MEM_CP_NULL;

jerry-core/lit/lit-literal.c

@@ -211,7 +211,7 @@ lit_find_or_create_literal_from_utf8_string (const lit_utf8_byte_t *str_p, /**<
  *
  * @return pointer to a newly created record
  */
-lit_literal_t __attr_always_inline___
+inline lit_literal_t __attr_always_inline___
 lit_create_literal_from_num (const ecma_number_t num) /**< number to initialize a new number literal */
 {
   return lit_create_number_literal (num);
@@ -592,7 +592,7 @@ lit_magic_literal_get_magic_str_ex_id (lit_literal_t lit) /**< literal */
   return (lit_magic_string_ex_id_t) rec_p->magic_id;
 } /* lit_magic_literal_get_magic_str_ex_id */
 
-lit_utf8_size_t __attr_always_inline___ __attr_pure___
+inline lit_utf8_size_t __attr_always_inline___ __attr_pure___
 lit_charset_literal_get_size (lit_literal_t lit) /**< literal */
 {
   JERRY_ASSERT (lit->type == LIT_RECORD_TYPE_CHARSET);
@@ -607,7 +607,7 @@ lit_charset_literal_get_size (lit_literal_t lit) /**< literal */
  *
  * @return code units count
  */
-ecma_length_t __attr_always_inline___ __attr_pure___
+inline ecma_length_t __attr_always_inline___ __attr_pure___
 lit_charset_literal_get_length (lit_literal_t lit) /**< literal */
 {
   JERRY_ASSERT (lit->type == LIT_RECORD_TYPE_CHARSET);
@@ -617,7 +617,7 @@ lit_charset_literal_get_length (lit_literal_t lit) /**< literal */
   return (ecma_length_t) rec_p->length;
 } /* lit_charset_literal_get_length */
 
-ecma_number_t __attr_always_inline___ __attr_pure___
+inline ecma_number_t __attr_always_inline___ __attr_pure___
 lit_number_literal_get_number (lit_literal_t lit) /**< literal */
 {
   JERRY_ASSERT (lit->type == LIT_RECORD_TYPE_NUMBER);
@@ -627,7 +627,7 @@ lit_number_literal_get_number (lit_literal_t lit) /**< literal */
   return rec_p->number;
 } /* lit_number_literal_get_number */
 
-lit_utf8_byte_t * __attr_always_inline___ __attr_pure___
+inline lit_utf8_byte_t * __attr_always_inline___ __attr_pure___
 lit_charset_literal_get_charset (lit_literal_t lit) /**< literal */
 {
   JERRY_ASSERT (lit->type == LIT_RECORD_TYPE_CHARSET);

jerry-core/lit/lit-strings.c

@@ -699,7 +699,7 @@ lit_utf8_decr (lit_utf8_byte_t **buf_p) /**< [in,out] buffer with characters */
  *
  * @return ecma-string's hash
  */
-lit_string_hash_t __attr_always_inline___
+inline lit_string_hash_t __attr_always_inline___
 lit_utf8_string_hash_combine (lit_string_hash_t hash_basis, /**< hash to be combined with */
                               const lit_utf8_byte_t *utf8_buf_p, /**< characters buffer */
                               lit_utf8_size_t utf8_buf_size) /**< number of characters in the buffer */
@@ -722,7 +722,7 @@ lit_utf8_string_hash_combine (lit_string_hash_t hash_basis, /**< hash to be comb
  *
  * @return ecma-string's hash
  */
-lit_string_hash_t __attr_always_inline___
+inline lit_string_hash_t __attr_always_inline___
 lit_utf8_string_calc_hash (const lit_utf8_byte_t *utf8_buf_p, /**< characters buffer */
                            lit_utf8_size_t utf8_buf_size) /**< number of characters in the buffer */
 {
@@ -763,7 +763,7 @@ lit_utf8_string_code_unit_at (const lit_utf8_byte_t *utf8_buf_p, /**< utf-8 stri
  *
  * @return number of bytes occupied in CESU-8
  */
-lit_utf8_size_t __attr_always_inline___
+inline lit_utf8_size_t __attr_always_inline___
 lit_get_unicode_char_size_by_utf8_first_byte (const lit_utf8_byte_t first_byte) /**< buffer with characters */
 {
   if ((first_byte & LIT_UTF8_1_BYTE_MASK) == LIT_UTF8_1_BYTE_MARKER)