vendor: update buildkit to v0.18.0-rc1

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/exemplar.go

@@ -0,0 +1,42 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
+
+import (
+	"sync"
+
+	"go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+)
+
+var exemplarPool = sync.Pool{
+	New: func() any { return new([]exemplar.Exemplar) },
+}
+
+func collectExemplars[N int64 | float64](out *[]metricdata.Exemplar[N], f func(*[]exemplar.Exemplar)) {
+	dest := exemplarPool.Get().(*[]exemplar.Exemplar)
+	defer func() {
+		*dest = (*dest)[:0]
+		exemplarPool.Put(dest)
+	}()
+
+	*dest = reset(*dest, len(*out), cap(*out))
+
+	f(dest)
+
+	*out = reset(*out, len(*dest), cap(*dest))
+	for i, e := range *dest {
+		(*out)[i].FilteredAttributes = e.FilteredAttributes
+		(*out)[i].Time = e.Time
+		(*out)[i].SpanID = e.SpanID
+		(*out)[i].TraceID = e.TraceID
+
+		switch e.Value.Type() {
+		case exemplar.Int64ValueType:
+			(*out)[i].Value = N(e.Value.Int64())
+		case exemplar.Float64ValueType:
+			(*out)[i].Value = N(e.Value.Float64())
+		}
+	}
+}