parser: allow types that start with &&; cgen: allow ++/-- exprs for now

vlib/v/parser/fn.v

@@ -186,7 +186,7 @@ fn (p mut Parser) fn_args() ([]table.Arg,bool) {
 	mut args := []table.Arg
 	mut is_variadic := false
 	// `int, int, string` (no names, just types)
-	types_only := p.tok.kind in [.amp] || (p.peek_tok.kind == .comma && p.table.known_type(p.tok.lit)) || p.peek_tok.kind == .rpar
+	types_only := p.tok.kind in [.amp, .and] || (p.peek_tok.kind == .comma && p.table.known_type(p.tok.lit)) || p.peek_tok.kind == .rpar
 	if types_only {
 		// p.warn('types only')
 		mut arg_no := 1

vlib/v/parser/parser.v

@@ -896,7 +896,7 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 				pos: p.tok.position()
 			}
 			p.next()
-			return node
+			// return node // TODO bring back, only allow ++/-- in exprs in translated code
 		}
 		else {
 			return node

vlib/v/tests/cstrings_test.v

@@ -1,3 +1,5 @@
+fn C.strlen() int
+
 fn test_cstring() {
 	w := c'world'
 	hlen := C.strlen(c'hello')