gopls/internal: use go1.24-isms

This CL intentionally does not include any new API covered by
the modernizers, whose fixes will be submitted separately.

Surprisingly few changes in all.

Change-Id: I0c45ed674fd80234e7c76823a23b8b3af3011835
Reviewed-on: https://go-review.googlesource.com/c/tools/+/651376
Auto-Submit: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Author: adonovan

gopls/internal/analysis/gofix/directive.go

@@ -12,7 +12,7 @@ import (
 
 // -- plundered from the future (CL 605517, issue #68021) --
 
-// TODO(adonovan): replace with ast.Directive after go1.24 (#68021).
+// TODO(adonovan): replace with ast.Directive after go1.25 (#68021).
 // Beware of our local mods to handle analysistest
 // "want" comments on the same line.
 

gopls/internal/golang/pkgdoc.go

@@ -39,7 +39,6 @@ import (
 	"go/token"
 	"go/types"
 	"html"
-	"iter"
 	"path/filepath"
 	"slices"
 	"strings"
@@ -666,7 +665,7 @@ window.addEventListener('load', function() {
 				cloneTparams(sig.RecvTypeParams()),
 				cloneTparams(sig.TypeParams()),
 				types.NewTuple(append(
-					slices.Collect(tupleVariables(sig.Params()))[:3],
+					slices.Collect(sig.Params().Variables())[:3],
 					types.NewParam(0, nil, "", types.Typ[types.Invalid]))...),
 				sig.Results(),
 				false) // any final ...T parameter is truncated
@@ -851,17 +850,3 @@ window.addEventListener('load', function() {
 
 	return buf.Bytes(), nil
 }
-
-// tupleVariables returns a go1.23 iterator over the variables of a tuple type.
-//
-// Example: for v := range tuple.Variables() { ... }
-// TODO(adonovan): use t.Variables in go1.24.
-func tupleVariables(t *types.Tuple) iter.Seq[*types.Var] {
-	return func(yield func(v *types.Var) bool) {
-		for i := range t.Len() {
-			if !yield(t.At(i)) {
-				break
-			}
-		}
-	}
-}

gopls/internal/test/integration/misc/references_test.go

@@ -126,7 +126,7 @@ var _ = unsafe.Slice(nil, 0)
 
 	Run(t, files, func(t *testing.T, env *Env) {
 		env.OpenFile("a.go")
-		for _, name := range strings.Fields(
+		for name := range strings.FieldsSeq(
 			"iota error int nil append iota Pointer Sizeof Alignof Add Slice") {
 			loc := env.RegexpSearch("a.go", `\b`+name+`\b`)