Set `-fno-strict-aliasing` when building with bazel.

Repro: `bazel test -c opt ...` breaking `CompilerTest.NoStrictAliasing`.

This flag is already set in the CMake build system, and not setting it
in an optimized build causes at least that test to fail. Until
bug #42290308 is fixed, we should keep `-fno-strict-aliasing` enabled.

Bug: 42290308
Bug: 454835295
Change-Id: I602997d546e81b36b23104efc0c5a2a13d02d451
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/83227
Reviewed-by: David Benjamin <davidben@google.com>
Auto-Submit: Rudolf Polzer <rpolzer@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

util/util.bzl

diff --git a/util/util.bzl b/util/util.bzl
index 8617488..c668089 100644
--- a/util/util.bzl
+++ b/util/util.bzl
@@ -28,6 +28,7 @@
     "-Wwrite-strings",
     "-Wshadow",
     "-fno-common",
+    "-fno-strict-aliasing",
 ]
 
 gcc_copts_cxx = [