[Bug c++/92271] for consistency, __is_same_as should be named __is_same

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92271

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Thu Dec  5 20:06:46 2019
New Revision: 279018

URL: https://gcc.gnu.org/viewcvs?rev=279018&root=gcc&view=rev
Log:
        PR c++/92271 - make __is_same alias for __is_same_as.

Richard Smith proposed adding a synonym for __is_same_as, to accomodate the
convention of exposing std::SOME_TRAIT<A, B>::value as __SOME_TRAIT(A, B).

So add that alias, and also adjust the C++ printer.  I didn't bother changing
the RID_ identifier.

        * c-common.c: Add __is_same, an alias for __is_same_as.

        * cxx-pretty-print.c (pp_cxx_trait_expression) <case CPTK_IS_SAME_AS>:
        Print "__is_same".

        * g++.dg/ext/is_same.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/ext/is_same.C
Modified:
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-common.c
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cxx-pretty-print.c
    trunk/gcc/testsuite/ChangeLog