[roll pigweed] pw_toolchain: Add logic to allow RBE for clang

This adds conditionalized logic for RBE in pigweed for
clang.  This will only be enabled if an environment variable
PW_USE_RBE is set to true.

Test: Verified the build worked with and without the
      environment variable was set.
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/99681

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: ef6820af98835c9..f78e864e2c5bbb2
Roller-URL: https://ci.chromium.org/b/8806986937014063265
Cq-Cl-Tag: roller-builder:pigweed-zephyr-roller
Cq-Cl-Tag: roller-bid:8806986937014063265
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Id05da4cb973aab0618244fd71d6f1ca1f227a99a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/104477
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>
1 file changed
tree: a2114eb522959bee6459b37be3957df5ea237197
  1. .gitmodules
  2. test.sh