[roll third_party/pigweed] pw_toolchain_bazel: Implement per-action files

This will allow us to deprecate the use of "ar_files",
"compile_files", "all_files", ...
This will make things much simpler, as it's rather confusing that,
for example, adding to all_files won't add it to compile_files.

Original-Bug: 322872628
Test: bazel build //cc_toolchain/tests/...
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/190152

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: e821637464c104e..a7e8a40c06c2ee5
Roller-URL: https://ci.chromium.org/b/8756699701108197057
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I14a9e40243cd0c205edbc97e4c71a867cafd94bb
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/190747
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 e821637..a7e8a40 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit e821637464c104e0d853632a81a6848b1f349f0c
+Subproject commit a7e8a40c06c2ee5d5cd5daa25b0832b4b87a42b2