inclhack.def (avoid_bool_define, [...]): Bypass with __cplusplus, not "we must use the C++ compiler's type"

	* fixinc/inclhack.def (avoid_bool_define, avoid_bool_type): Bypass
	with __cplusplus, not "we must use the C++ compiler's type"
	* fixinc/inclhack.def (void_null): Note that Interix needs this.
	* fixinc/fixincl.x: Regenerate.

From-SVN: r69373