roll: third_party/pigweed 5 commits

ddcc251bcac0c2c pw_toolchain: Rustc cross compile to qemu-clang
2bccf25ed3d181d pw_build: Fix configs in pw_rust_executable
61f6e54585a0e81 pw_rust: Add no_std build to basic_executable
79f0dd143867866 pw_rust: Rename host_executable
9d49c47bb21b0cc pw_env_setup: Add rustc thumbv7m target

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 55c5087185c0ff3..ddcc251bcac0c2c
Roller-URL: https://ci.chromium.org/b/8740841887869781393
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iad0a2095e1ea69062a531386467f8a5bb817b4f0
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/226858
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.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 55c5087..ddcc251 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 55c5087185c0ff3d9662283f3c0300ec82dabc3d
+Subproject commit ddcc251bcac0c2c20dfea39bed09683851587f99