[roll third_party/pigweed] roll: clang

From: git_revision:c58bc24fcf678c55b0bf522be89eff070507a005
To: git_revision:ca260e1b119b043195158098a9afda3967c6854b
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/193790
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: dcbf65b8a91ddaf..7a9b71ad0a5436e
Roller-URL: https://ci.chromium.org/b/8755181816937342689
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I529c2e301f54bb82d700b56336a2c37a24e6f341
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/193792
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 dcbf65b..7a9b71a 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit dcbf65b8a91ddafec6fbfaa16387eb313709159e
+Subproject commit 7a9b71ad0a5436e9b78998402fe1ad71007a7cd9