roll: third_party/pigweed 70a7885..fb0038e (3 commits)

fb0038e:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/312696 doxygen: Migrate pw_async2
b0387c4:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/314053 pw_toolchain: Make compiler-specific flags usable
905ec38:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/314019 pw_ide: Mention right targets for currently untracked files

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 70a7885506f1d0..fb0038e8510fd3
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8706157657689025665
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I0c78853a26984a2dc834f106f4ced8e6ae57621d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/314152
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 70a7885..fb0038e 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 70a7885506f1d03cbbe0d4e8b6a3965901958f58
+Subproject commit fb0038e8510fd3f2b85966074222d60041fdc599