2010-08-14 Ivan Maidanski <ivmai@mail.ru>

2010-08-14  Ivan Maidanski <ivmai@mail.ru>

	* os_dep.c (os2_alloc): Don't set PAG_EXECUTE unless
	pages_executable is on.
	* os_dep.c (os2_alloc): Add FIXME (for recursion).
	* os_dep.c (UNPROTECT): Abort with a more informative message if
	pages_executable is on ("mprotect" case).
	* os_dep.c (PROTECT, UNPROTECT): Set VM_PROT_EXEC if
	pages_executable is on (Darwin case).
	* pthread_support.c (GC_init_real_syms): Abort with an informative
	message if libgc is linked after libpthread.