check for typedef specifier/attribute not strict enough

[samkho]

The comment and code for line 423 of parse.c do not match. It seems the comment describes the correct behavior.

chibicc/parse.c

Line 423 in 90d1f7f

attr->is_static + attr->is_extern + attr->is_inline + attr->is_tls > 1)

 
The comparison "> 1" should instead be ">= 1" or "> 0" or "!= 0" . Also, it would be clearer if the four attr->is_.... bools are OR'd together instead of added.

1. gcc, clang, and chibicc all flag the following as illegal:

static inline typedef struct
{
int x;
int y;
} Point;

2. BUT chibicc allows the following which both gcc and clang flag as illegal:

static typedef struct
{
int x;
int y;
} Point;