Use test sharding to parallelise the tests. (#544)

Author: AdamHillier

larq_compute_engine/mlir/tests/lit_test.bzl

@@ -39,6 +39,7 @@ def lce_lit_test(
         srcs = [driver],
         size = size,
         data = data + [test_file],
+        shard_count = 2,
         args = ["$(location %s)" % (test_file,)],
         **kwargs
     )

larq_compute_engine/tests/qemu_test.bzl

@@ -35,10 +35,11 @@ def lce_qemu_test_suite(
         # Finally create a new sh_test target
         native.sh_test(
             name = sh_name,
-            size = "medium",
+            size = "large",
             srcs = [src],
             args = [test_path],
             data = [test, qemu_data],
+            shard_count = 2,
         )
 
         # And add that sh_test target to the list