Revert "Allow compilation of patterns to succeed even when the variables of...

Revert "Allow compilation of patterns to succeed even when the variables of the expected input type cannot be erased."

This reverts commit 439186cd.

This commit generates unsafe code that crashes easily at runtime.

types/patterns.ml

@@ -1403,15 +1403,9 @@ module Compile = struct
 
 
   let make_branches t b =
-    let open Debug in
-    _DEBUG "pat_comp" "@[make_branches type is: %a@]@\n" Types.Print.pp_type t;
     try
       make_branches t b
     with
-      FindCode ->
-      try
-	make_branches (Types.Subst.hide_vars t) b
-      with
-	FindCode -> make_branches Types.any b
+    FindCode -> make_branches (Types.Subst.hide_vars t) b
 
 end