generic sys_fork / sys_vfork / sys_clone

... and get rid of idiotic struct pt_regs * in asm-generic/syscalls.h
prototypes of the same, while we are at it.  Eventually we want those
in linux/syscalls.h, of course, but that'll have to wait a bit.

Note that there are *three* variants of sys_clone() order of arguments.
Braindamage galore...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/Kconfig b/arch/Kconfig
index 366ec06..8d698fb 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -341,4 +341,18 @@
 	  Modules only use ELF REL relocations.  Modules with ELF RELA
 	  relocations will give an error.
 
+#
+# ABI hall of shame
+#
+config CLONE_BACKWARDS
+	bool
+	help
+	  Architecture has tls passed as the 4th argument of clone(2),
+	  not the 5th one.
+
+config CLONE_BACKWARDS2
+	bool
+	help
+	  Architecture has the first two arguments of clone(2) swapped.
+
 source "kernel/gcov/Kconfig"