[yuyi98]

This PR fix formatting struct decl with comments (fix #20202).

• Fix formatting struct decl with comments.
• Add test.

struct ABC  //size: 0x1=1 (source) (123 45 67) 20B
{
        ff[0x20]                u8
}

fmt to:

struct ABC { // size: 0x1=1 (source) (123 45 67) 20B
	ff [0x20]u8
}

[spytheman]

Good work.