[roll third_party/pigweed] roll: clang

From: git_revision:725656bdd885483c39f482a01ea25d67acf39c46
To: git_revision:c58bc24fcf678c55b0bf522be89eff070507a005
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/189450
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: b2766fdb547f05d..f6956d5bd0d92aa
Roller-URL: https://ci.chromium.org/b/8757721458780203569
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I454e24ae6bd5845bf6958c4bfd3fc1cfbf8162d1
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/189451
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index b2766fd..f6956d5 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit b2766fdb547f05d2af2d7a730327001c6371d6e2
+Subproject commit f6956d5bd0d92aa437a12ad167ff88ad35d09843