runtime: remove the unused scanIdx from mspan

After CL 700496, mspan.scanIdx is never used, this CL just remove it.

Change-Id: I41ce9902957c0cfa6fbf26b66a2a7787b179376a
Reviewed-on: https://go-review.googlesource.com/c/go/+/737220
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Carlos Amedee <carlos@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index 68dfca4668602471695b9664e5e46b28978aeeda..9b62ee4273551f3322383ff5a6564e0ac2acc55b 100644 (file)
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -457,12 +457,6 @@ type mspan struct {
        // mallocgc, and issue 54596).
        freeIndexForScan uint16
 
-       // Temporary storage for the object index that caused this span to
-       // be queued for scanning.
-       //
-       // Used only with goexperiment.GreenTeaGC.
-       scanIdx uint16
-
        // Cache of the allocBits at freeindex. allocCache is shifted
        // such that the lowest bit corresponds to the bit freeindex.
        // allocCache holds the complement of allocBits, thus allowing