cmd/internal/obj/x86: fix VPERMQ and VPERMPD ytab

Fixes invalid encoding of VPERMQ and VPERMPD that use
negative immediate argument.

Fixes #25418
Updates #25420

Change-Id: Idd8180c4c632a76b76f3a68efd5f930d94431994
Reviewed-on: https://go-review.googlesource.com/113615
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>

src/cmd/asm/internal/asm/testdata/amd64enc_extra.s

@@ -294,8 +294,11 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	SHA256MSG2 X2, X11       // 440f38cdda
 	SHA256MSG2 X11, X11      // 450f38cddb
 	// Test VPERMQ with both uint8 and int8 immediate args
-	VPERMQ $-40, Y8, Y8 // c4407800c0d8
+	VPERMQ $-40, Y8, Y8 // c443fd00c0d8
 	VPERMQ $216, Y8, Y8 // c443fd00c0d8
+	// Test that VPERMPD that shares ytab list with VPERMQ continues to work too.
+	VPERMPD $-40, Y7, Y7 // c4e3fd01ffd8
+	VPERMPD $216, Y7, Y7 // c4e3fd01ffd8
 	// Check that LEAL is permitted to use overflowing offset.
 	LEAL 2400959708(BP)(R10*1), BP // 428dac15dcbc1b8f
 	LEAL 3395469782(AX)(R10*1), AX // 428d8410d6c162ca

src/cmd/internal/obj/x86/asm6.go

@@ -931,7 +931,7 @@ var yvex_xi3 = []ytab{
 }
 
 var yvex_vpermpd = []ytab{
-	{Zvex_i_rm_r, 2, argList{Yu8, Yym, Yyr}},
+	{Zvex_i_rm_r, 0, argList{Yu8, Yym, Yyr}},
 	// Allow int8 for backwards compatibility with negative values
 	// like $-1.
 	{Zvex_i_rm_r, 2, argList{Yi8, Yym, Yyr}},