Added ahal

This is a formatted copy of WPILib's default user-visible C++ API, with
a bit of completely unnecessary functionality stripped out. Most of the
stripping so far is only related to weird threading decisions.

Change-Id: Icbfd949b48cd115561862cb909bcc572aba0e753
diff --git a/third_party/BUILD b/third_party/BUILD
index 20bb7e0..934486e 100644
--- a/third_party/BUILD
+++ b/third_party/BUILD
@@ -1,7 +1,14 @@
 cc_library(
-  name = 'wpilib',
-  deps = ['//third_party/allwpilib_2018:wpilib'],
-  visibility = ['//visibility:public'],
-  linkstatic = True,
-  restricted_to = ['//tools:roborio'],
+    name = "wpilib",
+    linkstatic = True,
+    restricted_to = ["//tools:roborio"],
+    visibility = ["//visibility:public"],
+    deps = ["//frc971/wpilib/ahal"],
+)
+
+cc_library(
+    name = "wpilib_hal",
+    restricted_to = ["//tools:roborio"],
+    visibility = ["//visibility:public"],
+    deps = ["//third_party/allwpilib_2018:hal"],
 )