--watchfs for OSX: use kFSEventStreamCreateFlagNoDefer to receive event as soon as they arrives

See https://developer.apple.com/reference/coreservices/1455376-fseventstreamcreateflags/kfseventstreamcreateflagnodefer?language=objc

Also added the integration test now it is no more flaky.
Tested with `bazel test src/test/java/com/google/devtools/build/lib/skyframe:SkyframeTests --runs_per_test 10 --test_filter=com.google.devtools.build.lib.skyframe.MacOSXFsEventsDiffAwarenessTest --nocache_test_results`

Fixes #1362.

--
Change-Id: I42ceebd8c5a2e0156653b140ca049af45d2e1e80
Reviewed-on: https://bazel-review.googlesource.com/6613
MOS_MIGRATED_REVID=136078777

src/test/java/com/google/devtools/build/lib/skyframe/BUILD

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/BUILD b/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
index 04438e1..ff94116 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
@@ -41,9 +41,14 @@
 
 java_test(
     name = "SkyframeTests",
-    srcs = glob([
-        "*.java",
-    ]),
+    srcs = select({
+        "//src:darwin": glob(["*.java"]),
+        "//src:darwin_x86_64": glob(["*.java"]),
+        "//conditions:default": glob(
+            ["*.java"],
+            exclude = ["MacOSXFsEventsDiffAwarenessTest.java"],
+        ),
+    }),
     tags = ["skyframe"],
     test_class = "com.google.devtools.build.lib.AllTests",
     deps = [