Fix typos in documentation (regarding 'non-incremental')

* doc/gcdescr.md (Introduction): Fix typos ("non-incremental",
"this operation").
* mark.c (GC_collection_in_progress): Fix a typo in comment
("non-incremental").

1 files changed, 1 insertions, 1 deletions

diff --git a/mark.c b/mark.c
index 718aaf39..1812b943 100644
--- a/mark.c
+++ b/mark.c
@@ -123,7 +123,7 @@ STATIC GC_bool GC_objects_are_marked = FALSE;
                 /* Are there collectible marked objects in the heap?    */
 
 /* Is a collection in progress?  Note that this can return true in the  */
-/* nonincremental case, if a collection has been abandoned and the      */
+/* non-incremental case, if a collection has been abandoned and the     */
 /* mark state is now MS_INVALID.                                        */
 GC_INNER GC_bool GC_collection_in_progress(void)
 {