fmt: use fixed size array for max_len const

vlib/v/fmt/fmt.v

@@ -12,7 +12,7 @@ import v.pref
 const bs = '\\'
 
 // when to break a line depending on the penalty
-const max_len = [0, 35, 60, 85, 93, 100]
+const max_len = [0, 35, 60, 85, 93, 100]!
 
 @[minify]
 pub struct Fmt {
@@ -1696,7 +1696,7 @@ pub fn (mut f Fmt) sum_type_decl(node ast.SumTypeDecl) {
 	for variant in variants {
 		// 3 = length of ' = ' or ' | '
 		line_length += 3 + variant.name.len
-		if line_length > fmt.max_len.last() || (variant.id != node.variants.len - 1
+		if line_length > fmt.max_len[fmt.max_len.len - 1] || (variant.id != node.variants.len - 1
 			&& node.variants[variant.id].end_comments.len > 0) {
 			separator = '\n\t| '
 			is_multiline = true
@@ -1825,7 +1825,7 @@ pub fn (mut f Fmt) array_init(node ast.ArrayInit) {
 		single_line_expr := expr_is_single_line(expr)
 		if single_line_expr {
 			mut estr := ''
-			if !is_new_line && !f.buffering && f.line_len + expr.pos().len > fmt.max_len.last() {
+			if !is_new_line && !f.buffering && f.line_len + expr.pos().len > fmt.max_len[fmt.max_len.len - 1] {
 				if inc_indent {
 					estr = f.node_str(expr)
 				}
@@ -2379,7 +2379,7 @@ pub fn (mut f Fmt) if_expr(node ast.IfExpr) {
 		}
 		// When a single line if is really long, write it again as multiline,
 		// except it is part of an InfixExpr.
-		if is_ternary && f.line_len > fmt.max_len.last() && !f.buffering {
+		if is_ternary && f.line_len > fmt.max_len[fmt.max_len.len - 1] && !f.buffering {
 			is_ternary = false
 			f.single_line_if = false
 			f.out.go_back_to(start_pos)
@@ -2504,7 +2504,7 @@ pub fn (mut f Fmt) infix_expr(node ast.InfixExpr) {
 	}
 	if !buffering_save && f.buffering {
 		f.buffering = false
-		if !f.single_line_if && f.line_len > fmt.max_len.last() {
+		if !f.single_line_if && f.line_len > fmt.max_len[fmt.max_len.len - 1] {
 			is_cond := node.op in [.and, .logical_or]
 			f.wrap_infix(start_pos, start_len, is_cond)
 		}
@@ -2587,7 +2587,7 @@ fn (mut f Fmt) write_splitted_infix(conditions []string, penalties []int, ignore
 				f.write(c)
 				continue
 			}
-			if final_len > fmt.max_len.last() && is_paren_expr {
+			if final_len > fmt.max_len[fmt.max_len.len - 1] && is_paren_expr {
 				conds, pens := split_up_infix(c, true, is_cond)
 				f.write_splitted_infix(conds, pens, true, is_cond)
 				continue
@@ -2827,7 +2827,7 @@ pub fn (mut f Fmt) or_expr(node ast.OrExpr) {
 				// so, since this'll all be on one line, trim any possible whitespace
 				str := f.node_str(node.stmts[0]).trim_space()
 				single_line := ' or { ${str} }'
-				if single_line.len + f.line_len <= fmt.max_len.last() {
+				if single_line.len + f.line_len <= fmt.max_len[fmt.max_len.len - 1] {
 					f.write(single_line)
 					return
 				}

vlib/v/fmt/struct.v

@@ -330,7 +330,7 @@ pub fn (mut f Fmt) struct_init(node ast.StructInit) {
 				if single_line_fields && (init_field.comments.len > 0
 					|| init_field.next_comments.len > 0
 					|| !expr_is_single_line(init_field.expr)
-					|| f.line_len > max_len.last()) {
+					|| f.line_len > fmt.max_len[fmt.max_len.len - 1]) {
 					single_line_fields = false
 					f.out.go_back_to(fields_start)
 					f.line_len = fields_start