selfhost: port forrange — N_FORRANGE parser + cgen + tuple destructure

test/wcc/994_w6c_ww.c

@@ -178,6 +178,27 @@ main(void)
 		  "  append(dst, src...);\n"
 		  "  return dst.len: i32;\n"
 		  "};" },
+		{ "forrange",
+		  "use os;\n"
+		  "fn main() i32 = {\n"
+		  "  let s: []u8;\n"
+		  "  s.ptr = nil; s.len = 0; s.cap = 0;\n"
+		  "  append(s, 10u8, 20u8, 30u8);\n"
+		  "  let total: i32 = 0;\n"
+		  "  for (let b .. s) { total += b: i32; };\n"
+		  "  return total;\n"
+		  "};" },
+		{ "forrange_tuple",
+		  "fn main() i32 = {\n"
+		  "  let buf: [4]i64;\n"
+		  "  buf[0] = 1i64; buf[1] = 10i64; buf[2] = 2i64; buf[3] = 20i64;\n"
+		  "  let s: [](i64, i64);\n"
+		  "  s.ptr = buf.ptr: *(i64, i64);\n"
+		  "  s.len = 2; s.cap = 2;\n"
+		  "  let total: i64 = 0i64;\n"
+		  "  for (let (k, v) .. s) { total += k + v; };\n"
+		  "  return total: i32;\n"
+		  "};" },
 		{ NULL, NULL },
 	};