Store span of method receiver colon tokens
diff --git a/syntax/mod.rs b/syntax/mod.rs
index b2c524b..96aa4c9 100644
--- a/syntax/mod.rs
+++ b/syntax/mod.rs
@@ -185,6 +185,7 @@
     pub mutable: bool,
     pub var: Token![self],
     pub ty: NamedType,
+    pub colon_token: Token![:],
     pub shorthand: bool,
     pub pin_tokens: Option<(kw::Pin, Token![<], Token![>])>,
     pub mutability: Option<Token![mut]>,