cmd/internal/tesdir: fix Test/codegen/switch on loong64

loong64 uses ALSLV the compute the lookup index.

Fixes #78575

Change-Id: Ied90a4f811cc19ffec4d304333546d1fa430ccc0
Reviewed-on: https://go-review.googlesource.com/c/go/+/764180
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>

test/codegen/switch.go

diff --git a/test/codegen/switch.go b/test/codegen/switch.go
index 2178627..baeb7cb 100644
--- a/test/codegen/switch.go
+++ b/test/codegen/switch.go
@@ -134,7 +134,6 @@
 func stringLookup(x int) string {
 	// amd64:`LEAQ .*\(SB\)` -`JMP \(.*\)\(.*\)$`
 	// arm64:-`JMP \(R.*\)$`
-	// loong64:-`ALSLV`
 	switch x {
 	case 1:
 		return "a"
@@ -161,7 +160,6 @@
 func complexLookup(x int) complex128 {
 	// amd64:`LEAQ .*\(SB\)` -`JMP \(.*\)\(.*\)$`
 	// arm64:-`JMP \(R.*\)$`
-	// loong64:-`ALSLV`
 	switch x {
 	case 1:
 		return 1 + 2i