Change object representation from 1 big union to individual structs.
A big change. Micro Python objects are allocated as individual structs
with the first element being a pointer to the type information (which
is itself an object). This scheme follows CPython. Much more flexible,
not necessarily slower, uses same heap memory, and can allocate objects
statically.
Also change name prefix, from py_ to mp_ (mp for Micro Python).
diff --git a/unix/lexerunix.h b/unix/lexerunix.h
index aa7631c..d86f202 100644
--- a/unix/lexerunix.h
+++ b/unix/lexerunix.h
@@ -1,2 +1,2 @@
-py_lexer_t *py_lexer_new_from_str_len(const char *src_name, const char *str, uint len, bool free_str);
-py_lexer_t *py_lexer_new_from_file(const char *filename);
+mp_lexer_t *mp_lexer_new_from_str_len(const char *src_name, const char *str, uint len, bool free_str);
+mp_lexer_t *mp_lexer_new_from_file(const char *filename);