fmt: keep lines of comments inside an array (#8420)

vlib/v/fmt/fmt.v

@@ -1929,8 +1929,16 @@ pub fn (mut f Fmt) array_init(it ast.ArrayInit) {
 		}
 		f.expr(expr)
 		if i < it.ecmnts.len && it.ecmnts[i].len > 0 {
-			f.write(' ')
+			mut last_cmt := it.ecmnts[i][0]
+			if last_cmt.pos.line_nr > expr.position().last_line {
+				f.writeln('')
+			} else {
+				f.write(' ')
+			}
 			for cmt in it.ecmnts[i] {
+				if cmt.pos.line_nr > last_cmt.pos.last_line {
+					f.writeln('')
+				}
 				f.comment(cmt, iembed: true)
 			}
 		}

vlib/v/fmt/tests/comments_embedded_keep.vv

@@ -0,0 +1,12 @@
+fn only_comments_array() {
+	arr := [
+		/* 1, */
+		/* 2, */
+		/* 3, */
+		/* 4, */
+	]
+	arr2 := [
+		/* 1, */ /* 2, *//* 3, */
+		/* 4, */
+	]
+}

vlib/v/fmt/tests/comments_expected.vv

@@ -40,7 +40,8 @@ fn main() {
 	e := c
 	// more comments = more good
 	arr := [
-		/* block foo bar */ /* inline foo bar */
+		/* block foo bar */
+		/* inline foo bar */
 		0,
 	]
 	// before arg comment