Converting ecma_value_t to class that is used for on-stack storage of ecma-values.

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.

src/libcoreint/opcodes-ecma-support.h

@@ -31,6 +31,7 @@
 #include "ecma-operations.h"
 #include "ecma-reference.h"
 #include "ecma-try-catch-macro.h"
+#include "ecma-value.h"
 #include "deserializer.h"
 
 bool is_reg_variable (int_data_t *int_data, idx_t var_idx);