all: replace Split in loops with more efficient SplitSeq

Find these replacements through https://pkg.go.dev/golang.org/x/tools/gopls/internal/analysis/modernize.

Change-Id: If88fe0e109b7c7557bfb3d3ffc15271af1ab5856
Reviewed-on: https://go-review.googlesource.com/c/go/+/668437
Reviewed-by: Sean Liao <sean@liao.dev>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: David Chase <drchase@google.com>

src/compress/flate/example_test.go

@@ -175,7 +175,7 @@ func Example_synchronization() {
 		}
 
 		b := make([]byte, 256)
-		for _, m := range strings.Fields("A long time ago in a galaxy far, far away...") {
+		for m := range strings.FieldsSeq("A long time ago in a galaxy far, far away...") {
 			// We use a simple framing format where the first byte is the
 			// message length, followed the message itself.
 			b[0] = uint8(copy(b[1:], m))

src/go/ast/ast.go

@@ -134,10 +134,10 @@ func (g *CommentGroup) Text() string {
 		}
 
 		// Split on newlines.
-		cl := strings.Split(c, "\n")
+		cl := strings.SplitSeq(c, "\n")
 
 		// Walk lines, stripping trailing white space and adding to list.
-		for _, l := range cl {
+		for l := range cl {
 			lines = append(lines, stripTrailingWhitespace(l))
 		}
 	}

src/log/slog/slogtest_test.go

@@ -43,7 +43,7 @@ func TestSlogtest(t *testing.T) {
 
 func parseLines(src []byte, parse func([]byte) (map[string]any, error)) ([]map[string]any, error) {
 	var records []map[string]any
-	for _, line := range bytes.Split(src, []byte{'\n'}) {
+	for line := range bytes.SplitSeq(src, []byte{'\n'}) {
 		if len(line) == 0 {
 			continue
 		}