[RFC v2 -tip 0/3] x86: reduce fixup of uaccess

[Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>]

This patch series redues fixup code for exceptions of uaccess in signal.

There is a lot of fixup code which is generated by using __{get|put}_user.
I think that code can be reduced. The concept is that to add uaccess_err in
thread_info and set it to -EFAULT on exception, finally check this value on
the last of function.

The code size reductions are below;
$ size *signal*.o.*
   text	   data	    bss	    dec	    hex	filename
   4596	      0	      0	   4596	   11f4	ia32_signal.o.new
   6006	      0	      0	   6006	   1776	ia32_signal.o.old
   3583	      0	      0	   3583	    dff	signal.o.new
   4540	      0	      0	   4540	   11bc	signal.o.old
   3863	      0	      0	   3863	    f17	signal32.o.new
   4876	      0	      0	   4876	   130c	signal32.o.old
[ signal32.o means signal.o on 32-bit. ]

ChangeLog v1 -> v2
	- Change framework syntax. Previous version doesn't look easy to read.
	  Remove parens from try and add redundant braces as Peter suggested.
		get_user_try {
			get_user_ex(...);
			:
		} get_user_catch(err);
	- Remove double underscores.