gdb/
* arch-utils.c (default_return_in_first_hidden_param_p): New.
* arch-utils.h: Declare.
* gdbarch.sh: Add return_in_first_hidden_param_p.
* gdbarch.c, gdbarch.h: Regenerated.
* infcall.c (call_function_by_hand): Call
gdbarch_return_in_first_hidden_param_p instead of
language_pass_by_reference.
* m68k-tdep.c (m68k_return_in_first_hidden_param_p): New.
(m68k_gdbarch_init): Install m68k_return_in_first_hidden_param_p.
* sh-tdep.c (sh_return_in_first_hidden_param_p): New.
(sh_gdbarch_init): Install sh_return_in_first_hidden_param_p.
* tic6x-tdep.c (tic6x_push_dummy_call): Remove local variable
`cplus_return_struct_by_reference'.
(tic6x_return_value): Handle language cplusplus.
(tic6x_return_in_first_hidden_param_p): New.
(tic6x_gdbarch_init): Install tic6x_return_in_first_hidden_param_p.