vfmt: fix removal of selective imported type used in map (#12030)

vlib/v/fmt/fmt.v

@@ -245,6 +245,12 @@ pub fn (mut f Fmt) short_module(name string) string {
 
 pub fn (mut f Fmt) mark_types_import_as_used(typ ast.Type) {
 	sym := f.table.get_type_symbol(typ)
+	if sym.info is ast.Map {
+		map_info := sym.map_info()
+		f.mark_types_import_as_used(map_info.key_type)
+		f.mark_types_import_as_used(map_info.value_type)
+		return
+	}
 	name := sym.name.split('<')[0] // take `Type` from `Type<T>`
 	f.mark_import_as_used(name)
 }

vlib/v/fmt/tests/import_selective_expected.vv

@@ -18,6 +18,8 @@ import mod {
 	RightOfIs,
 	StructEmbed,
 	StructField,
+	StructMapFieldKey,
+	StructMapFieldValue,
 	StructMethodArg,
 	StructMethodArgGeneric,
 	StructMethodRet,
@@ -29,6 +31,7 @@ struct Struct {
 	StructEmbed
 	v   StructField
 	ref &StructRefField
+	map map[StructMapFieldKey]StructMapFieldValue
 }
 
 fn (s Struct) method(v StructMethodArg) StructMethodRet {

vlib/v/fmt/tests/import_selective_input.vv

@@ -10,6 +10,7 @@ import os {
 import mod {
 	Unused,
 	StructEmbed, StructField, StructRefField
+	StructMapFieldKey, StructMapFieldValue,
 	StructMethodArg,
 	StructMethodArgGeneric,
 	StructMethodRet,
@@ -34,6 +35,7 @@ struct Struct {
 	StructEmbed
 	v StructField
 	ref &StructRefField
+	map map[StructMapFieldKey]StructMapFieldValue
 }
 
 fn (s Struct) method(v StructMethodArg) StructMethodRet {