Check link presence without resolving arena indexes

A presence query needs only the page entry, not its value. Resolving
an occupied index adds arena lookup work to a boolean check.

Keep presence checks on the compressed page table, and apply the
repository linter fixes to the link-store tests.

tsc/internal/core/linkstore.go

@@ -69,7 +69,8 @@ func (s *PagedLinkStore[V]) Get(key uint64) *V {
 }
 
 func (s *PagedLinkStore[V]) Has(key uint64) bool {
-	return s.TryGet(key) != nil
+	pageIndex := key >> LinkPageShift
+	return int(pageIndex) < len(s.pages) && s.pages[pageIndex] != nil && s.pages[pageIndex][key&LinkPageMask] != 0
 }
 
 func (s *PagedLinkStore[V]) TryGet(key uint64) *V {

tsc/internal/core/linkstore_test.go

@@ -1,8 +1,8 @@
 package core_test
 
 import (
-	"fmt"
 	"runtime"
+	"strconv"
 	"testing"
 
 	"github.com/microsoft/TypeScript/tsc/internal/core"
@@ -113,17 +113,17 @@ func TestIndexedArenaReachability(t *testing.T) {
 	var arena core.IndexedArena[*string]
 	for i := range 4096 {
 		_, value := arena.New()
-		*value = new(fmt.Sprint(i))
+		*value = new(strconv.Itoa(i))
 	}
 	runtime.GC()
 	for i := range 4096 {
-		assert.Equal(t, **arena.Get(uint32(i + 1)), fmt.Sprint(i))
+		assert.Equal(t, **arena.Get(uint32(i + 1)), strconv.Itoa(i))
 	}
 }
 
 func BenchmarkPagedLinkStore(b *testing.B) {
 	for _, stride := range []uint64{1, 16, 256} {
-		b.Run(fmt.Sprint(stride), func(b *testing.B) {
+		b.Run(strconv.FormatUint(stride, 10), func(b *testing.B) {
 			type value struct {
 				typ   *int
 				flags uint32