runtime: typo fix cyle -> cycle

Change-Id: I213fa8aa9b9c2537a189677394ddd30c62312518
GitHub-Last-Rev: ccafdee944
GitHub-Pull-Request: golang/go#50268
Reviewed-on: https://go-review.googlesource.com/c/go/+/373336
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Zhuo Meng <mzh@golangcn.org>

src/runtime/mgcmark.go

@@ -1561,7 +1561,7 @@ func gcmarknewobject(span *mspan, obj, size, scanSize uintptr) {
 	if !goexperiment.PacerRedesign {
 		// The old pacer counts newly allocated memory toward
 		// heapScanWork because heapScan is continuously updated
-		// throughout the GC cyle with newly allocated memory. However,
+		// throughout the GC cycle with newly allocated memory. However,
 		// these objects are never actually scanned, so we need
 		// to account for them in heapScanWork here, "faking" their work.
 		// Otherwise the pacer will think it's always behind, potentially

src/runtime/mgcsweep.go

@@ -393,7 +393,7 @@ func sweepone() uintptr {
 		// The scavenger is signaled by the last sweeper because once
 		// sweeping is done, we will definitely have useful work for
 		// the scavenger to do, since the scavenger only runs over the
-		// heap once per GC cyle. This update is not done during sweep
+		// heap once per GC cycle. This update is not done during sweep
 		// termination because in some cases there may be a long delay
 		// between sweep done and sweep termination (e.g. not enough
 		// allocations to trigger a GC) which would be nice to fill in