[roll third_party/pigweed] roll: gn

From: git_revision:182a6eb05d15cc76d2302f7928fdb4f645d52c53
To: git_revision:5d8727f3fbf420538ff753ebc3ce96da28e12c22
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/177330
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 45fbd96e68ce3eb..8c8719939903452
Roller-URL: https://ci.chromium.org/b/8766500897214991745
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I93dda28f542b022ee2608637b4702c07ff1913b3
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/kudzu/+/177350
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 45fbd96..8c87199 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 45fbd96e68ce3eb65ad49bc8e8683abff07b3a2b
+Subproject commit 8c871993990345226ebeefcc1b78a44e9bf4aa6e