[roll third_party/pigweed] pw_build_info: Add GNU build ID support

Introduces the pw_build_info module, and adds support for reading GNU
build IDs from python and from inside the context of a C++ application.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/53760

third_party/pigweed Rolled-Commits: 81017fe1af1f6a9..6954a8dfa1bb49b
Roller-URL: https://ci.chromium.org/b/8839718764042185520
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8839718764042185520
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I3519bd427754e1367b7c0006bf67e7f38e4eb605
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/56221
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 81017fe..6954a8d 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 81017fe1af1f6a985c8634af8864ea64ecfeb9c3
+Subproject commit 6954a8dfa1bb49b9cc9f07254aabaa87a64ef43e