[third_party/pigweed] Roll 2 commits

ee592559959ed84 pw_polyfill: Remove C++11 and C11 polyfills
5768d5d05c62058 pw_system: Add native system target

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 242a27cc3b30338..ee592559959ed84
Roller-URL: https://ci.chromium.org/b/8825397491247670625
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8825397491247670625
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ie657150724d4130e826fc2f33c619fadf8865f94
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/77748
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 242a27c..ee59255 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 242a27cc3b3033898b4ead86d16dfef765cfe5b4
+Subproject commit ee592559959ed84ae4496a325a796b9ec5f6bc8b