cmd/asm: move manual tests out of generated file

Thanks to Iskander Sharipov for spotting this in an earlier CL of mine.

Change-Id: Idf45ad266205ff83985367cb38f585badfbed151
Reviewed-on: https://go-review.googlesource.com/100535
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/asm/internal/asm/testdata/amd64enc.s

@@ -8742,8 +8742,6 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	VPERMQ $7, (R11), Y11                   // c443fd001b07
 	VPERMQ $7, Y2, Y11                      // c463fd00da07
 	VPERMQ $7, Y11, Y11                     // c443fd00db07
-	VPERMQ $-40, Y8, Y8                     // c4407800c0d8
-	VPERMQ $216, Y8, Y8                     // c443fd00c0d8
 	VPEXTRB $7, X2, (BX)                    // c4e379141307
 	VPEXTRB $7, X11, (BX)                   // c46379141b07
 	VPEXTRB $7, X2, (R11)                   // c4c379141307

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

@@ -293,5 +293,8 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
 	SHA256MSG2 (R11), X11    // 450f38cd1b
 	SHA256MSG2 X2, X11       // 440f38cdda
 	SHA256MSG2 X11, X11      // 450f38cddb
+	// Test VPERMQ with both uint8 and int8 immediate args
+	VPERMQ $-40, Y8, Y8 // c4407800c0d8
+	VPERMQ $216, Y8, Y8 // c443fd00c0d8
 	// End of tests.
 	RET