tcc: fix selfcompilation with tcc. Temporarily disable crashing interface test

vlib/builtin/string.v

@@ -43,10 +43,10 @@ NB: A V string should be/is immutable from the point of view of
 
 
 pub struct string {
-	is_lit bool
 pub:
 	str byteptr // points to a C style 0 terminated string of bytes.
 	len int // the length of the .str field, excluding the ending 0 byte. It is always equal to strlen(.str).
+	is_lit bool
 }
 	// mut:
 	// hash_cache int

vlib/v/parser/fn.v

@@ -125,8 +125,10 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 		if !rec_mut {
 			rec_mut = p.tok.kind == .key_mut
 		}
-		is_amp := p.tok.kind == .amp
+        
 		receiver_pos = rec_start_pos.extend(p.tok.position())
+		is_amp := p.tok.kind == .amp
+
 		// if rec_mut {
 		// p.check(.key_mut)
 		// }