[PATCH] consolidate sys_ptrace()

The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.

Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations.  For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.

Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Paul Mackerras <[email protected]>
Acked-by: Ralf Baechle <[email protected]>
Acked-By: David Howells <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: Paul Mundt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/asm-ia64/ptrace.h

@@ -229,6 +229,9 @@ struct switch_stack {
 };
 
 #ifdef __KERNEL__
+
+#define __ARCH_SYS_PTRACE	1
+
 /*
  * We use the ia64_psr(regs)->ri to determine which of the three
  * instructions in bundle (16 bytes) took the sample. Generate