Fix decoding buckets for native histograms in binops

The optimizer which detects cases where histogram buckets can be skipped
does not take into account binary expressions. This can lead to buckets
not being decoded if a metric is used with both histogram_fraction/quantile and
histogram_sum/count in the same expression.

Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>

promql/engine.go

@@ -3450,6 +3450,12 @@ func setOffsetForAtModifier(evalTime int64, expr parser.Expr) {
 // required for correctness.
 func detectHistogramStatsDecoding(expr parser.Expr) {
 	parser.Inspect(expr, func(node parser.Node, path []parser.Node) error {
+		if n, ok := node.(*parser.BinaryExpr); ok {
+			detectHistogramStatsDecoding(n.LHS)
+			detectHistogramStatsDecoding(n.RHS)
+			return fmt.Errorf("stop")
+		}
+
 		n, ok := (node).(*parser.VectorSelector)
 		if !ok {
 			return nil

promql/promqltest/testdata/native_histograms.test

@@ -715,6 +715,9 @@ eval instant at 10m histogram_fraction(NaN, NaN, histogram_fraction_4)
 eval instant at 10m histogram_fraction(-Inf, +Inf, histogram_fraction_4)
     {} 1
 
+eval instant at 10m histogram_sum(scalar(histogram_fraction(-Inf, +Inf, sum(histogram_fraction_4))) * histogram_fraction_4)
+    {} 100
+
 clear
 
 # Counter reset only noticeable in a single bucket.