replace array with an actual struct now that we have them

examples/curl.zr

@@ -1,14 +1,14 @@
 func main[argc: i64, argv: ptr] : i64
     if argc < 2
-        dbg.panic("url missing")
+        panic("url missing")
 
     let url: str = mem.read64(argv + 8)
 
     if str.len(url) <= 7
-        dbg.panic("missing url scheme")
+        panic("missing url scheme")
 
     if !str.equal(str.substr(url, 0, 7), "http://")
-        dbg.panic("invalid url scheme")
+        panic("invalid url scheme")
     
     let url_len: i64 = str.len(url)
     let host_start = 7
@@ -25,7 +25,7 @@ func main[argc: i64, argv: ptr] : i64
 
     let s: i64 = net.connect(host, 80)
     if s < 0
-        dbg.panic("failed to connect")
+        panic("failed to connect")
 
     // very leaky
     let req: str = "GET "