parser: support `mut static x := y` in -translated mode

vlib/v/checker/tests/static_vars_in_translated_mode.out

@@ -0,0 +1,6 @@
+vlib/v/checker/tests/static_vars_in_translated_mode.vv:2:13: error: static variables are supported only in -translated mode
+    1 | fn counter() int {
+    2 |     mut static icounter := 0
+      |                ~~~~~~~~
+    3 |     icounter++
+    4 |     return icounter

vlib/v/checker/tests/static_vars_in_translated_mode.vv

@@ -0,0 +1,12 @@
+fn counter() int {
+	mut static icounter := 0
+	icounter++
+	return icounter
+}
+
+fn main() {
+	println(counter())
+	println(counter())
+	println(counter())
+	println(counter())
+}

vlib/v/fmt/fmt.v

@@ -263,6 +263,9 @@ pub fn (mut f Fmt) stmt(node ast.Stmt) {
 					if var_info.is_mut {
 						f.write(var_info.share.str() + ' ')
 					}
+					if var_info.is_static {
+						f.write('static ')
+					}
 					f.expr(left)
 				} else {
 					f.expr(left)

vlib/v/parser/assign.v

@@ -105,6 +105,7 @@ fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comme
 			}
 		}
 	}
+	mut is_static := false
 	for i, lx in left {
 		match mut lx {
 			ast.Ident {
@@ -114,7 +115,14 @@ fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comme
 					}
 					mut share := table.ShareType(0)
 					if lx.info is ast.IdentVar {
-						share = (lx.info as ast.IdentVar).share
+						iv := lx.info as ast.IdentVar
+						share = iv.share
+						if iv.is_static {
+							if !p.pref.translated {
+								p.error_with_pos('static variables are supported only in -translated mode', lx.pos)
+							}
+							is_static = true
+						}
 					}
 					mut v := ast.Var{
 						name: lx.name
@@ -157,5 +165,6 @@ fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comme
 		pos: pos
 		has_cross_var: has_cross_var
 		is_simple: p.inside_for && p.tok.kind == .lcbr
+		is_static: is_static
 	}
 }