Original ecma_value_t is renamed to ecma_value_packed_t and is used for on-heap storage.
Copy and move constructors, move assignment operator of ecma_value_t are not created.
New ecma-value return convention is introduced: ecma-values are now returned through ecma_value_t &ret_val argument.
Add internal hash map of literal indexes:
In this hash map key is pair of block number and literal's unique identifier in the block, and the value is a literal index that unique in the whole program.
Block is a continues array of opcodes. So, bytecode is splitted into blocks.
Each block has its own uid counter. To get literal index the interpreter looks up it in the hash map.
Thus, now JS program is able to have more than 255 identifiers/string literals.
The first 128 (0-127) uids are reserved for block's uid counter, the other 128 (128-255) are reserved for tmp variables.
Ruben Ayrapetyan