* Fix#2772: allow non-comparable global types
The global MeterProvider, TracerProvider, and TextMapPropagator should
not panic when they are set to a non-comparable implementation of each.
* Add changes to changelog
* No lint unused field for testing
* WIP: add global API
* WIP
* Add a global meter.
* moved global access out of metric because of loop imports
* fix linting issues
* remove changes from other lint failures.
* Add changelog
* Fixes for comments.
Changed name of global API.
Added stop to all race tests go routine.
Added race tests for other instruments.
* Apply suggestions from code review
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
* Consolidated instrument tests
* fixed lint, and removed unneeded type checking
* change require's to asserts.
* Update misspelling
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
* Fix meter race test.
* Copy SetTracerProvider logic.
* Fix global test for panic.
* Fix linting error
* bump testify version
* moved changelog into unreleased
Co-authored-by: Aaron Clawson <MadVikingGod@users.noreply.github.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>