tools: let v fmt use VTMP too, stabilise v test-cleancode

vlib/v/builder/compile.v

@@ -9,21 +9,8 @@ import rand
 import v.pref
 import v.util
 
-fn get_vtmp_folder() string {
-	mut vtmp := os.getenv('VTMP')
-	if vtmp.len > 0 {
-		return vtmp
-	}
-	vtmp = os.join_path(os.temp_dir(), 'v')
-	if !os.exists(vtmp) || !os.is_dir(vtmp) {
-		os.mkdir_all(vtmp)
-	}
-	os.setenv('VTMP', vtmp, true)
-	return vtmp
-}
-
 fn (mut b Builder) get_vtmp_filename(base_file_name string, postfix string) string {
-	vtmp := get_vtmp_folder()
+	vtmp := util.get_vtmp_folder()
 	mut uniq := ''
 	if !b.pref.reuse_tmpc {
 		uniq = '.$rand.u64()'

vlib/v/util/util.v

@@ -462,6 +462,19 @@ pub fn recompile_file(vexe string, file string) {
 	}
 }
 
+pub fn get_vtmp_folder() string {
+	mut vtmp := os.getenv('VTMP')
+	if vtmp.len > 0 {
+		return vtmp
+	}
+	vtmp = os.join_path(os.temp_dir(), 'v')
+	if !os.exists(vtmp) || !os.is_dir(vtmp) {
+		os.mkdir_all(vtmp)
+	}
+	os.setenv('VTMP', vtmp, true)
+	return vtmp
+}
+
 pub fn should_bundle_module(mod string) bool {
 	return mod in bundle_modules || (mod.contains('.') && mod.all_before('.') in bundle_modules)
 }