add .bazelrc

This lets us set up --configs for build variants.  E.g.

    bazel test --config=asan ...
    bazel test --config=msan ...
    bazel test --config=clang ...

    bazel run bench
    100000 loops in 5.36636e+06 clock ticks, 210 ns / pixel

    bazel run -c opt bench
    100000 loops in 1.23995e+06 clock ticks, 48.6 ns / pixel

    bazel run -c opt --config=clang bench
    100000 loops in 437699 clock ticks, 17.2 ns / pixel

Notice how --config=msan itself uses --config=clang.

Change-Id: Ib0f778a6e65a8fb76466453e703f79c1e31404b1
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/304851
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/.bazelrc b/.bazelrc
new file mode 100644
index 0000000..dc8766e
--- /dev/null
+++ b/.bazelrc
@@ -0,0 +1,9 @@
+build:clang --action_env=CC=clang
+build:clang --action_env=CXX=clang++
+
+build:asan --copt -fsanitize=address
+build:asan --linkopt -fsanitize=address
+
+build:msan --config=clang
+build:msan --copt -fsanitize=memory
+build:msan --linkopt -fsanitize=memory