indent(1): add fallthrough markers

This silences -Wimplicit-fallthrough warnings.

Submitted by:	Michael Paquier
Obtained from:	postgresql.org
MFC after:	3 days

usr.bin/indent/indent.c

@@ -967,6 +967,7 @@ main(int argc, char **argv)
 	case structure:
 	    if (ps.p_l_follow > 0)
 		goto copy_id;
+	    /* FALLTHROUGH */
 	case decl:		/* we have a declaration type (int, etc.) */
 	    parse(decl);	/* let parser worry about indentation */
 	    if (ps.last_token == rparen && ps.tos <= 1) {

usr.bin/indent/parse.c

@@ -107,6 +107,7 @@ parse(int tk) /* tk: the code for the construct scanned */
 		 */
 		ps.i_l_follow = ps.il[ps.tos--];
 	/* the rest is the same as for dolit and forstmt */
+	/* FALLTHROUGH */
     case dolit:		/* 'do' */
     case forstmt:		/* for (...) */
 	ps.p_stack[++ps.tos] = tk;