Booleans can be used in a switch

compiler/heptagon/parsing/hept_parser.mly

@@ -341,10 +341,14 @@ escapes:
 ;
 
 switch_handler:
-  | constructor loc_vars DO equs
+  | constructor_or_bool loc_vars DO equs
       { { w_name = $1; w_block = mk_block $2 $4 } }
 ;
 
+constructor_or_bool:
+  | BOOL { Name(if $1 then "true" else "false") }
+  | constructor { $1 }
+
 switch_handlers:
   | switch_handler
       { [$1] }