x86: Fix to decode grouped AVX with VEX pp bits

Fix to decode grouped AVX with VEX pp bits which should be
handled as same as last-prefixes. This fixes below warnings
in posttest with CONFIG_CRYPTO_SHA1_SSSE3=y.

 Warning: arch/x86/tools/test_get_len found difference at <sha1_transform_avx>:ffffffff810d5fc0
 Warning: ffffffff810d6069:	c5 f9 73 de 04       	vpsrldq $0x4,%xmm6,%xmm0
 Warning: objdump says 5 bytes, but insn_get_length() says 4
 ...

With this change, test_get_len can decode it correctly.

 $ arch/x86/tools/test_get_len -v -y
 ffffffff810d6069:       c5 f9 73 de 04          vpsrldq $0x4,%xmm6,%xmm0
 Succeed: decoded and checked 1 instructions

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120210053340.30429.73410.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/inat.h b/arch/x86/include/asm/inat.h
index 205b063..74a2e31 100644
--- a/arch/x86/include/asm/inat.h
+++ b/arch/x86/include/asm/inat.h
@@ -97,11 +97,12 @@
 
 /* Attribute search APIs */
 extern insn_attr_t inat_get_opcode_attribute(insn_byte_t opcode);
+extern int inat_get_last_prefix_id(insn_byte_t last_pfx);
 extern insn_attr_t inat_get_escape_attribute(insn_byte_t opcode,
-					     insn_byte_t last_pfx,
+					     int lpfx_id,
 					     insn_attr_t esc_attr);
 extern insn_attr_t inat_get_group_attribute(insn_byte_t modrm,
-					    insn_byte_t last_pfx,
+					    int lpfx_id,
 					    insn_attr_t esc_attr);
 extern insn_attr_t inat_get_avx_attribute(insn_byte_t opcode,
 					  insn_byte_t vex_m,