vfmt: support `x := chan Name{cap: 123}`

vlib/v/fmt/fmt.v

@@ -804,14 +804,7 @@ pub fn (mut f Fmt) expr(node ast.Expr) {
 			f.call_expr(node)
 		}
 		ast.ChanInit {
-			f.write('chan[')
-			f.write(f.type_to_str(node.elem_type))
-			f.write(']{')
-			if node.has_cap {
-				f.write('cap: ')
-				f.expr(node.cap_expr)
-			}
-			f.write('}')
+			f.chan_init(mut node)
 		}
 		ast.CharLiteral {
 			f.write('`$node.val`')
@@ -1623,6 +1616,21 @@ fn expr_is_single_line(expr ast.Expr) bool {
 	return true
 }
 
+pub fn (mut f Fmt) chan_init(mut it ast.ChanInit) {
+	if it.elem_type == 0 && it.typ > 0 {
+		info := f.table.get_type_symbol(it.typ).chan_info()
+		it.elem_type = info.elem_type
+	}
+	f.write('chan ')
+	f.write(f.type_to_str(it.elem_type))
+	f.write('{')
+	if it.has_cap {
+		f.write('cap: ')
+		f.expr(it.cap_expr)
+	}
+	f.write('}')
+}
+
 pub fn (mut f Fmt) array_init(it ast.ArrayInit) {
 	if it.exprs.len == 0 && it.typ != 0 && it.typ != table.void_type {
 		// `x := []string`

vlib/v/fmt/tests/chan_init_keep.vv

@@ -0,0 +1,11 @@
+import sync
+
+struct FSMEvent {
+	x int
+}
+
+fn main() {
+	ch_fsm_events := chan FSMEvent{cap: 1000}
+	eprintln('ch_fsm_events.len: $ch_fsm_events.len')
+	eprintln('ch_fsm_events.cap: $ch_fsm_events.cap')
+}