fix(testing): dont pause timer in b.Loop()

Author: not-matthias

testing/testing/benchmark.go

@@ -552,7 +552,6 @@ func (b *B) loopSlowPath() bool {
 // whereas b.N-based benchmarks must run the benchmark function (and any
 // associated setup and cleanup) several times.
 func (b *B) Loop() bool {
-	b.StopTimer()
 	// This is written such that the fast path is as fast as possible and can be
 	// inlined.
 	//
@@ -567,7 +566,6 @@ func (b *B) Loop() bool {
 	//   path can do consistency checks and fail.
 	if b.loop.i < b.loop.n {
 		b.loop.i++
-		b.StartTimer()
 		return true
 	}
 	return b.loopSlowPath()