fixes

src/token.zig

@@ -37,6 +37,7 @@ pub const Tag = enum {
     kw_impl, // impl
     kw_Self, // Self (in protocol declarations)
     kw_inline, // inline (compile-time if/for/while)
+    kw_callconv, // callconv (calling convention annotation)
 
     // Symbols
     colon, // :
@@ -227,6 +228,7 @@ pub const keywords = std.StaticStringMap(Tag).initComptime(.{
     .{ "impl", .kw_impl },
     .{ "Self", .kw_Self },
     .{ "inline", .kw_inline },
+    .{ "callconv", .kw_callconv },
 });
 
 pub fn getKeyword(bytes: []const u8) ?Tag {