chore: Fix Loki arm builds (#15936)

Signed-off-by: Christian Haudum <christian.haudum@gmail.com>

pkg/dataobj/internal/dataset/dataset_iter.go

@@ -2,7 +2,6 @@ package dataset
 
 import (
 	"context"
-	"math"
 
 	"github.com/grafana/loki/v3/pkg/dataobj/internal/result"
 )
@@ -26,7 +25,7 @@ func Iter(ctx context.Context, columns []Column) result.Seq[Row] {
 	// more efficient implementation is needed for reading Datasets backed by
 	// object storage.
 
-	totalRows := math.MinInt64
+	var totalRows int
 	for _, col := range columns {
 		totalRows = max(totalRows, col.ColumnInfo().RowsCount)
 	}

pkg/dataobj/internal/dataset/value_encoding_bitmap.go

@@ -364,7 +364,7 @@ type bitpackBuffer struct {
 
 	width int
 
-	sets int    // Number of encoded sets. Each set has 8 elements.
+	sets uint64 // Number of encoded sets. Each set has 8 elements.
 	data []byte // Total amount of data.
 }
 
@@ -409,7 +409,7 @@ func (b *bitpackBuffer) Flush(w streamio.Writer) error {
 	//
 	// To encode the width in 6 bits, we encode width-1. That reserves the bottom
 	// 7 bits for metadata, and the remaining 57 bits for the number of sets.
-	const maxSets = 1<<57 - 1
+	const maxSets uint64 = 1<<57 - 1
 
 	// Validate constraints for safety.
 	switch {
@@ -423,7 +423,7 @@ func (b *bitpackBuffer) Flush(w streamio.Writer) error {
 
 	// Width can be between 1 and 64. To pack it into 6 bits, we subtract 1 from
 	// the value.
-	header := (uint64(b.sets) << 7) | (uint64(b.width-1) << 1) | 1
+	header := (b.sets << 7) | (uint64(b.width-1) << 1) | 1
 	if err := streamio.WriteUvarint(w, header); err != nil {
 		return err
 	}