feat(loong64): encode the full LSX and LASX table

Assisted-by: GLM 5.3 Flash

testdata/verify/vector_arith_sat_loong64.s

@@ -0,0 +1,132 @@
+// Differential kernel: the arith_sat vector slice against the Go
+// toolchain's loong64enc1.s rows (gasm v. go tool asm, byte for byte).
+
+#include "textflag.h"
+
+TEXT ·VSADDB(SB), NOSPLIT, $0
+	VSADDB V1, V2, V3
+	RET
+
+TEXT ·VSADDH(SB), NOSPLIT, $0
+	VSADDH V1, V2, V3
+	RET
+
+TEXT ·VSADDW(SB), NOSPLIT, $0
+	VSADDW V1, V2, V3
+	RET
+
+TEXT ·VSADDV(SB), NOSPLIT, $0
+	VSADDV V1, V2, V3
+	RET
+
+TEXT ·VSSUBB(SB), NOSPLIT, $0
+	VSSUBB V1, V2, V3
+	RET
+
+TEXT ·VSSUBH(SB), NOSPLIT, $0
+	VSSUBH V1, V2, V3
+	RET
+
+TEXT ·VSSUBW(SB), NOSPLIT, $0
+	VSSUBW V1, V2, V3
+	RET
+
+TEXT ·VSSUBV(SB), NOSPLIT, $0
+	VSSUBV V1, V2, V3
+	RET
+
+TEXT ·XVSADDB(SB), NOSPLIT, $0
+	XVSADDB X3, X2, X1
+	RET
+
+TEXT ·XVSADDH(SB), NOSPLIT, $0
+	XVSADDH X3, X2, X1
+	RET
+
+TEXT ·XVSADDW(SB), NOSPLIT, $0
+	XVSADDW X3, X2, X1
+	RET
+
+TEXT ·XVSADDV(SB), NOSPLIT, $0
+	XVSADDV X3, X2, X1
+	RET
+
+TEXT ·XVSSUBB(SB), NOSPLIT, $0
+	XVSSUBB X3, X2, X1
+	RET
+
+TEXT ·XVSSUBH(SB), NOSPLIT, $0
+	XVSSUBH X3, X2, X1
+	RET
+
+TEXT ·XVSSUBW(SB), NOSPLIT, $0
+	XVSSUBW X3, X2, X1
+	RET
+
+TEXT ·XVSSUBV(SB), NOSPLIT, $0
+	XVSSUBV X3, X2, X1
+	RET
+
+TEXT ·VSADDBU(SB), NOSPLIT, $0
+	VSADDBU V1, V2, V3
+	RET
+
+TEXT ·VSADDHU(SB), NOSPLIT, $0
+	VSADDHU V1, V2, V3
+	RET
+
+TEXT ·VSADDWU(SB), NOSPLIT, $0
+	VSADDWU V1, V2, V3
+	RET
+
+TEXT ·VSADDVU(SB), NOSPLIT, $0
+	VSADDVU V1, V2, V3
+	RET
+
+TEXT ·VSSUBBU(SB), NOSPLIT, $0
+	VSSUBBU V1, V2, V3
+	RET
+
+TEXT ·VSSUBHU(SB), NOSPLIT, $0
+	VSSUBHU V1, V2, V3
+	RET
+
+TEXT ·VSSUBWU(SB), NOSPLIT, $0
+	VSSUBWU V1, V2, V3
+	RET
+
+TEXT ·VSSUBVU(SB), NOSPLIT, $0
+	VSSUBVU V1, V2, V3
+	RET
+
+TEXT ·XVSADDBU(SB), NOSPLIT, $0
+	XVSADDBU X1, X2, X3
+	RET
+
+TEXT ·XVSADDHU(SB), NOSPLIT, $0
+	XVSADDHU X1, X2, X3
+	RET
+
+TEXT ·XVSADDWU(SB), NOSPLIT, $0
+	XVSADDWU X1, X2, X3
+	RET
+
+TEXT ·XVSADDVU(SB), NOSPLIT, $0
+	XVSADDVU X1, X2, X3
+	RET
+
+TEXT ·XVSSUBBU(SB), NOSPLIT, $0
+	XVSSUBBU X1, X2, X3
+	RET
+
+TEXT ·XVSSUBHU(SB), NOSPLIT, $0
+	XVSSUBHU X1, X2, X3
+	RET
+
+TEXT ·XVSSUBWU(SB), NOSPLIT, $0
+	XVSSUBWU X1, X2, X3
+	RET
+
+TEXT ·XVSSUBVU(SB), NOSPLIT, $0
+	XVSSUBVU X1, X2, X3
+	RET