Add jerryscript-compiler.h public header to cover compiler incompatibilities (#2313)

In general, public headers should not have compiler-specific
constructs but both the core and the port headers have attributes,
which are non-standard. It's better to factor out such constructs
to a common place (a new header) and hide them behind macros, which
can then be defined on a per-compiler basis.

This patch moves the existing definitions of function attributes and
likely/unlikely builtins to the new header. At the same time, it
unifies the names of these attribute defines and where they are
used. Moreover, it touches on jerry-main and removes the uses of
`__attribute__((unused))` entirely and replaces them with the
elsewhere used `(void) ...` pattern.

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

jerry-core/parser/js/js-parser-statm.c

@@ -701,7 +701,7 @@ parser_parse_while_statement_start (parser_context_t *context_p) /**< context */
 /**
  * Parse while statement (ending part).
  */
-static void __attr_noinline___
+static void JERRY_ATTR_NOINLINE
 parser_parse_while_statement_end (parser_context_t *context_p) /**< context */
 {
   parser_while_statement_t while_statement;
@@ -947,7 +947,7 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
 /**
  * Parse for statement (ending part).
  */
-static void __attr_noinline___
+static void JERRY_ATTR_NOINLINE
 parser_parse_for_statement_end (parser_context_t *context_p) /**< context */
 {
   parser_for_statement_t for_statement;
@@ -1028,7 +1028,7 @@ parser_parse_for_statement_end (parser_context_t *context_p) /**< context */
 /**
  * Parse switch statement (starting part).
  */
-static void __attr_noinline___
+static void JERRY_ATTR_NOINLINE
 parser_parse_switch_statement_start (parser_context_t *context_p) /**< context */
 {
   parser_switch_statement_t switch_statement;
@@ -2202,7 +2202,7 @@ parser_parse_statements (parser_context_t *context_p) /**< context */
 /**
  * Free jumps stored on the stack if a parse error is occured.
  */
-void __attr_noinline___
+void JERRY_ATTR_NOINLINE
 parser_free_jumps (parser_stack_iterator_t iterator) /**< iterator position */
 {
   while (true)

jerry-core/parser/js/js-parser.c

@@ -1228,7 +1228,7 @@ parse_print_final_cbc (ecma_compiled_code_t *compiled_code_p, /**< compiled code
   }
 
   byte_code_start_p += (unsigned int) (literal_end - register_end) * sizeof (ecma_value_t);
-  if (unlikely (compiled_code_p->status_flags & CBC_CODE_FLAGS_NON_STRICT_ARGUMENTS_NEEDED))
+  if (JERRY_UNLIKELY (compiled_code_p->status_flags & CBC_CODE_FLAGS_NON_STRICT_ARGUMENTS_NEEDED))
   {
     byte_code_start_p += argument_end * sizeof (ecma_value_t);
   }

jerry-core/parser/regexp/re-bytecode.c

@@ -123,7 +123,7 @@ re_bytecode_list_insert (re_bytecode_ctx_t *bc_ctx_p, /**< RegExp bytecode conte
  *
  * @return ecma character
  */
-inline ecma_char_t __attr_always_inline___
+inline ecma_char_t JERRY_ATTR_ALWAYS_INLINE
 re_get_char (uint8_t **bc_p) /**< pointer to bytecode start */
 {
   ecma_char_t chr;
@@ -137,7 +137,7 @@ re_get_char (uint8_t **bc_p) /**< pointer to bytecode start */
  *
  * @return current RegExp opcode
  */
-inline re_opcode_t __attr_always_inline___
+inline re_opcode_t JERRY_ATTR_ALWAYS_INLINE
 re_get_opcode (uint8_t **bc_p) /**< pointer to bytecode start */
 {
   uint8_t bytecode = **bc_p;
@@ -150,7 +150,7 @@ re_get_opcode (uint8_t **bc_p) /**< pointer to bytecode start */
  *
  * @return opcode parameter
  */
-inline uint32_t __attr_always_inline___
+inline uint32_t JERRY_ATTR_ALWAYS_INLINE
 re_get_value (uint8_t **bc_p) /**< pointer to bytecode start */
 {
   uint32_t value;
@@ -164,7 +164,7 @@ re_get_value (uint8_t **bc_p) /**< pointer to bytecode start */
  *
  * @return bytecode length (unsigned integer)
  */
-inline uint32_t __attr_pure___ __attr_always_inline___
+inline uint32_t JERRY_ATTR_PURE JERRY_ATTR_ALWAYS_INLINE
 re_get_bytecode_length (re_bytecode_ctx_t *bc_ctx_p) /**< RegExp bytecode context */
 {
   return ((uint32_t) (bc_ctx_p->current_p - bc_ctx_p->block_start_p));

jerry-core/parser/regexp/re-bytecode.h

@@ -103,7 +103,7 @@ typedef struct
 re_opcode_t re_get_opcode (uint8_t **bc_p);
 ecma_char_t re_get_char (uint8_t **bc_p);
 uint32_t re_get_value (uint8_t **bc_p);
-uint32_t re_get_bytecode_length (re_bytecode_ctx_t *bc_ctx_p) __attr_pure___;
+uint32_t JERRY_ATTR_PURE re_get_bytecode_length (re_bytecode_ctx_t *bc_ctx_p);
 
 void re_append_opcode (re_bytecode_ctx_t *bc_ctx_p, re_opcode_t opcode);
 void re_append_u32 (re_bytecode_ctx_t *bc_ctx_p, uint32_t value);

jerry-core/parser/regexp/re-parser.c

@@ -68,7 +68,7 @@ re_hex_lookup (re_parser_ctx_t *parser_ctx_p, /**< RegExp parser context */
  * @return true - if non-greedy character found
  *         false - otherwise
  */
-static inline bool __attr_always_inline___
+static inline bool JERRY_ATTR_ALWAYS_INLINE
 re_parse_non_greedy_char (re_parser_ctx_t *parser_ctx_p) /**< RegExp parser context */
 {
   if (parser_ctx_p->input_curr_p < parser_ctx_p->input_end_p