[roll third_party/pigweed] pw_build: Use -ffile-prefix-map by default

By default, Clang and GCC use file paths directly as provided for debug
symbols and macros like __FILE__. This means that binaries produced on
different machines can be different and may include undesireable info
like usernames.

Clang and GCC provide the -ffile-prefix-map option to strip non-portable
prefixes from filenames. Add a config that applies -ffile-prefix-map to
Pigweed builds by default.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/52340

third_party/pigweed Rolled-Commits: 1e4d13743318eca..ea55939d82ddcb4
Roller-URL: https://ci.chromium.org/b/8842263706679082448
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8842263706679082448
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ic93e98b620ae97ede1936377faf56d437f82a504
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/52400
Reviewed-by: 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 1e4d137..ea55939 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 1e4d13743318ecab6ceeb47497c11ea9d1f6a733
+Subproject commit ea55939d82ddcb462e6d319082435ef5a0aff773