"expected direct declarator" error in top-level unnamed struct declaration

[feroldi]

Code:

typedef struct { int i; } S_t;

Error:

test.c:1:23: error: expected declarator
typedef struct { int i; } S_t;
                      ^
test.c:1:23: note: direct declarator instead of this ';'
typedef struct { int i; } S_t;
                      ^