Uppercase type arguments don't work in inlined records

[DZakh]

type_id_6<'T, 'E> = | Ok('T) | Err({payload: 'E})

It works for 'T, but not for 'E

Errors:

Did you mean `e` instead of `E`?

The type variable name '_ is not allowed in programs

[cristianoc]

Likely enough to do:

diff --git a/jscomp/syntax/src/res_core.ml b/jscomp/syntax/src/res_core.ml
index 48023f378..6f1d4c688 100644
--- a/jscomp/syntax/src/res_core.ml
+++ b/jscomp/syntax/src/res_core.ml
@@ -4056,7 +4056,9 @@ and parse_type_var_list p =
     match p.Parser.token with
     | SingleQuote ->
       Parser.next p;
-      let lident, loc = parse_lident p in
+      let lident, loc =
+        parse_ident ~msg:ErrorMessages.type_param ~start_pos:p.start_pos p
+      in