Fixed to #include correct 32-bit headers; Refreshed libc/kernel headers

This patch fixes an issue where 64-bit hreaders are incorrectly included
in kernel headers.  For example, file "libc/kernel/arch-x86/asm/io.h"
incorreclty includes "io_64.h" (missing, BTW) instead of "io_32.h".

The reason is because CONFIG_X86_32 isn't considered pre-defined in
"kernel_default_arch_macros" for x86, and clean_header.py doesn't
look at it at all anyway (ie. __i386__ is also ignored, but it's
okay since x86 cross compiler defines it back)

Fixed 2 tools/*py, README.TXT, and refreshed libc/kernel headers

Change-Id: Iac834cc8b3548f055d3f2a214af36072dd679fe8
diff --git a/libc/kernel/arch-x86/asm/elf.h b/libc/kernel/arch-x86/asm/elf.h
index ac01942..2d1edfd 100644
--- a/libc/kernel/arch-x86/asm/elf.h
+++ b/libc/kernel/arch-x86/asm/elf.h
@@ -27,53 +27,24 @@
 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef struct user_i387_struct elf_fpregset_t;
-#ifdef __i386__
 typedef struct user_fxsr_struct elf_fpxregset_t;
 #define R_386_NONE 0
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_32 1
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_PC32 2
 #define R_386_GOT32 3
 #define R_386_PLT32 4
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_COPY 5
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_GLOB_DAT 6
 #define R_386_JMP_SLOT 7
 #define R_386_RELATIVE 8
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_GOTOFF 9
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define R_386_GOTPC 10
 #define R_386_NUM 11
 #define ELF_CLASS ELFCLASS32
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define ELF_DATA ELFDATA2LSB
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define ELF_ARCH EM_386
-#else
-#define R_X86_64_NONE 0  
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define R_X86_64_64 1  
-#define R_X86_64_PC32 2  
-#define R_X86_64_GOT32 3  
-#define R_X86_64_PLT32 4  
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define R_X86_64_COPY 5  
-#define R_X86_64_GLOB_DAT 6  
-#define R_X86_64_JUMP_SLOT 7  
-#define R_X86_64_RELATIVE 8  
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define R_X86_64_GOTPCREL 9  
-#define R_X86_64_32 10  
-#define R_X86_64_32S 11  
-#define R_X86_64_16 12  
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define R_X86_64_PC16 13  
-#define R_X86_64_8 14  
-#define R_X86_64_PC8 15  
-#define R_X86_64_NUM 16
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define ELF_CLASS ELFCLASS64
-#define ELF_DATA ELFDATA2LSB
-#define ELF_ARCH EM_X86_64
-#endif
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif