[ruby-cvs:78937] 863dbb21d8 (master): assume C99

卜部昌平	2019-12-02 14:48:42 +0900 (Mon, 02 Dec 2019)

  New Revision: 863dbb21d8

  https://github.com/ruby/ruby/commit/863dbb21d8

  Log:
    assume C99
    
    Now that we no longer support old compilers, we can safely delete
    several obsolete #ifdef gurads.  Also because (as of writing) it is
    impossible to compile the program using C++ compilers, lets just
    entirely prohibit __cplusplus to reduce # of LOCs.
    
    Note however that we still cannot eliminate __STDC_VERSION__ checks,
    because MSVC does not define it, saying its C99 support is partial.
    See also https://social.msdn.microsoft.com/Forums/vstudio/en-US/53a4fd75-9f97-48b2-aa63-2e2e5a15efa3

  Modified files:
    internal.h
    internal/serial.h