Initialization of __WCHAR_TYPE__ in cppinit.c

[David Edelsohn]

>>>>> Geoff Keating writes:

Geoff> A better way to do this is to define NO_BUILTIN_WCHAR_TYPE, and then
Geoff> define __WCHAR_TYPE__ in CPP_PREDEFINES based on whether -maix64 was
Geoff> supplied or not (and presumably also keyed off -fshort-wchar, so that
Geoff> users can override it).

	Why shouldn't wchar_t be a builtin type?  I'm really worried about
allowing users this much flexibility when it is defined in the OS ABI.  It
seems like it's just inviting trouble.

David