Separate build target for rtc_base/numerics/safe_minmax.h

So that we can avoid dependency cycles.

Bug: none
Change-Id: I821d9f1319dff01403d6e4e310cbb2d4b2b125e8
Reviewed-on: https://webrtc-review.googlesource.com/60500
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22328}
diff --git a/audio/BUILD.gn b/audio/BUILD.gn
index 0d8ca07..12760d4 100644
--- a/audio/BUILD.gn
+++ b/audio/BUILD.gn
@@ -80,6 +80,7 @@
     "../rtc_base:rtc_base",
     "../rtc_base:rtc_base_approved",
     "../rtc_base:rtc_task_queue",
+    "../rtc_base:safe_minmax",
     "../rtc_base:stringutils",
     "../system_wrappers",
     "../system_wrappers:field_trial_api",