py: Remove unnecessary RULE_none and PN_none from parser.

py/compile.c

@@ -49,7 +49,6 @@
 // TODO need to mangle __attr names
 
 typedef enum {
-    PN_none = 0,
 #define DEF_RULE(rule, comp, kind, ...) PN_##rule,
 #include "grammar.h"
 #undef DEF_RULE
@@ -2903,7 +2902,6 @@ STATIC void compile_yield_expr(compiler_t *comp, mp_parse_node_struct_t *pns) {
 
 typedef void (*compile_function_t)(compiler_t*, mp_parse_node_struct_t*);
 STATIC compile_function_t compile_function[] = {
-    NULL,
 #define nc NULL
 #define c(f) compile_##f
 #define DEF_RULE(rule, comp, kind, ...) comp,

py/emitinlinethumb.c

@@ -45,7 +45,6 @@
 #if MICROPY_EMIT_INLINE_THUMB
 
 typedef enum {
-    PN_none = 0,
 #define DEF_RULE(rule, comp, kind, ...) PN_##rule,
 #include "grammar.h"
 #undef DEF_RULE

py/parse.c

@@ -68,7 +68,6 @@ typedef struct _rule_t {
 } rule_t;
 
 enum {
-    RULE_none = 0,
 #define DEF_RULE(rule, comp, kind, ...) RULE_##rule,
 #include "grammar.h"
 #undef DEF_RULE
@@ -105,7 +104,6 @@ enum {
 #undef DEF_RULE
 
 STATIC const rule_t *rules[] = {
-    NULL,
 #define DEF_RULE(rule, comp, kind, ...) &rule_##rule,
 #include "grammar.h"
 #undef DEF_RULE