runtime: retype mheap.reclaimCredit as atomic.Uintptr

runtime: retype mheap.reclaimCredit as atomic.Uintptr

[git-generate]
cd src/runtime
mv export_test.go export.go
GOROOT=$(dirname $(dirname $PWD)) rf '
  add mheap.reclaimCredit \
// reclaimCredit is spare credit for extra pages swept. Since \
// the page reclaimer works in large chunks, it may reclaim \
// more than requested. Any spare pages released go to this \
// credit pool. \
reclaimCredit_ atomic.Uintptr
  ex {
    import "runtime/internal/atomic"

    var t mheap
    var v, w uintptr
    var d uintptr

    t.reclaimCredit -> t.reclaimCredit_.Load()
    t.reclaimCredit = v -> t.reclaimCredit_.Store(v)
    atomic.Loaduintptr(&t.reclaimCredit) -> t.reclaimCredit_.Load()
    atomic.LoadAcquintptr(&t.reclaimCredit) -> t.reclaimCredit_.LoadAcquire()
    atomic.Storeuintptr(&t.reclaimCredit, v) -> t.reclaimCredit_.Store(v)
    atomic.StoreReluintptr(&t.reclaimCredit, v) -> t.reclaimCredit_.StoreRelease(v)
    atomic.Casuintptr(&t.reclaimCredit, v, w) -> t.reclaimCredit_.CompareAndSwap(v, w)
    atomic.Xchguintptr(&t.reclaimCredit, v) -> t.reclaimCredit_.Swap(v)
    atomic.Xadduintptr(&t.reclaimCredit, d) -> t.reclaimCredit_.Add(d)
  }
  rm mheap.reclaimCredit
  mv mheap.reclaimCredit_ mheap.reclaimCredit
'
mv export.go export_test.go

Change-Id: I2c567781a28f5d8c2275ff18f2cf605b82f22d09
Reviewed-on: https://go-review.googlesource.com/c/go/+/356712
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>