Improve ecma_string_t descriptor (#3016)

This patch introduces several changes conntect to ecma-strings:
 - Extend the size of the reference counter to 28 bytes from 13
 - Extend the size of the string hash to 32 bytes from 16 to use the extact FNV-1a hash
 - Introduce ECMA_STATIC_STRING_FLAG to reduce the number of string ref/derefs for static strings.
 - Introduce ECMA_STRING_CONTAINER_ASCII_STRING to store run-time allocated ASCII strings more efficiently
 - Remove ECMA_STRING_CONTAINER_LIT_NUMBER to half the storage size of the parsing time allocated floating point numbers
 - Rework the global number storage, to store only the floating point numbers
 - Optimize the lookup in the global number/string/symbol tables via reduce the number of NULL checks during decompressing the next element pointers
 - Reduce the code duplication in ecma_concat_ecma_strings and ecma_append_chars_to_string
 - Improve ecma_string_get_char with optional arguments to make it more reusable.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

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

@@ -275,6 +275,8 @@ parser_module_context_init (void)
 
     const lit_utf8_byte_t *path_str_chars_p = ecma_string_get_chars (path_str_p,
                                                                      &path_str_size,
+                                                                     NULL,
+                                                                     NULL,
                                                                      &flags);
 
     ecma_string_t *path_p = ecma_module_create_normalized_path (path_str_chars_p,