[bugfix] Downstep otel to fix freebsd compile issue (#1773)

https://github.com/open-telemetry/opentelemetry-go/issues/4076

vendor/go.opentelemetry.io/otel/metric/global/global.go

@@ -0,0 +1,42 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/metric/global"
+
+import (
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/internal/global"
+)
+
+// Meter returns a Meter from the global MeterProvider. The
+// instrumentationName must be the name of the library providing
+// instrumentation. This name may be the same as the instrumented code only if
+// that code provides built-in instrumentation. If the instrumentationName is
+// empty, then a implementation defined default name will be used instead.
+//
+// This is short for MeterProvider().Meter(name).
+func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	return MeterProvider().Meter(instrumentationName, opts...)
+}
+
+// MeterProvider returns the registered global meter provider.
+// If none is registered then a No-op MeterProvider is returned.
+func MeterProvider() metric.MeterProvider {
+	return global.MeterProvider()
+}
+
+// SetMeterProvider registers `mp` as the global meter provider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	global.SetMeterProvider(mp)
+}