Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/quote/tests/ui/not-quotable.stderr

@@ -0,0 +1,20 @@
+error[E0277]: the trait bound `Ipv4Addr: ToTokens` is not satisfied
+ --> tests/ui/not-quotable.rs:6:13
+  |
+6 |     let _ = quote! { #ip };
+  |             ^^^^^^^^^^^^^^
+  |             |
+  |             the trait `ToTokens` is not implemented for `Ipv4Addr`
+  |             required by a bound introduced by this call
+  |
+  = help: the following other types implement trait `ToTokens`:
+            bool
+            char
+            isize
+            i8
+            i16
+            i32
+            i64
+            i128
+          and $N others
+  = note: this error originates in the macro `quote` (in Nightly builds, run with -Z macro-backtrace for more info)