Introduce unstable, incomplete WASM support

src/into_url.rs

@@ -37,14 +37,16 @@ impl<'a> PolyfillTryInto for &'a String {
     }
 }
 
-pub(crate) fn expect_uri(url: &Url) -> hyper::Uri {
-    url.as_str()
-        .parse()
-        .expect("a parsed Url should always be a valid Uri")
-}
+if_hyper! {
+    pub(crate) fn expect_uri(url: &Url) -> http::Uri {
+        url.as_str()
+            .parse()
+            .expect("a parsed Url should always be a valid Uri")
+    }
 
-pub(crate) fn try_uri(url: &Url) -> Option<hyper::Uri> {
-    url.as_str().parse().ok()
+    pub(crate) fn try_uri(url: &Url) -> Option<http::Uri> {
+        url.as_str().parse().ok()
+    }
 }
 
 #[cfg(test)]