parse: Note that fact that parser's small ints are different than VM small int.

Specifically, VM's small ints are 31 bit, while parser's only 28. There's already
MP_OBJ_FITS_SMALL_INT(), so, for clarity, rename MP_FIT_SMALL_INT() to
MP_PARSE_FITS_SMALL_INT().

py/compile.c

@@ -117,7 +117,7 @@ mp_parse_node_t fold_constants(mp_parse_node_t pn) {
                         assert(0);
                         res = 0;
                     }
-                    if (MP_FIT_SMALL_INT(res)) {
+                    if (MP_PARSE_FITS_SMALL_INT(res)) {
                         pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, res);
                     }
                 }

py/parse.c

@@ -279,7 +279,7 @@ STATIC void push_result_token(parser_t *parser, const mp_lexer_t *lex) {
         }
         if (dec) {
             pn = mp_parse_node_new_leaf(MP_PARSE_NODE_DECIMAL, qstr_from_strn(str, len));
-        } else if (small_int && !overflow && MP_FIT_SMALL_INT(int_val)) {
+        } else if (small_int && !overflow && MP_PARSE_FITS_SMALL_INT(int_val)) {
             pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, int_val);
         } else {
             pn = mp_parse_node_new_leaf(MP_PARSE_NODE_INTEGER, qstr_from_strn(str, len));

py/parse.h

@@ -14,7 +14,8 @@ struct _mp_lexer_t;
 // makes sure the top 5 bits of x are all cleared (positive number) or all set (negavite number)
 // these macros can probably go somewhere else because they are used more than just in the parser
 #define MP_UINT_HIGH_5_BITS (~((~((machine_uint_t)0)) >> 5))
-#define MP_FIT_SMALL_INT(x) (((((machine_uint_t)(x)) & MP_UINT_HIGH_5_BITS) == 0) || ((((machine_uint_t)(x)) & MP_UINT_HIGH_5_BITS) == MP_UINT_HIGH_5_BITS))
+// parser's small ints are different from VM small int
+#define MP_PARSE_FITS_SMALL_INT(x) (((((machine_uint_t)(x)) & MP_UINT_HIGH_5_BITS) == 0) || ((((machine_uint_t)(x)) & MP_UINT_HIGH_5_BITS) == MP_UINT_HIGH_5_BITS))
 
 #define MP_PARSE_NODE_NULL      (0)
 #define MP_PARSE_NODE_ID        (0x1)