* exp_ch11.adb:
(Expand_Exception_Handlers): Call Make_Exception_Handler instead of
Make_Implicit_Exception_Handler when rewriting an exception handler with
a choice parameter, and pass the handler's Sloc instead of that of the
handled sequence of statements. Make_Implicit_Exception_Handler sets the
Sloc to No_Location (unless debugging generated code), which we don't
want for the case of a user handler.