Update PathPackageLocator to take a list of potential build file names,
instead of assuming BUILD.

- Default the list to the same value as PackageLookupFunction:
  BUILD.bazel, BUILD.
- Move BuildFileNames to the packages package, so it is more generally
available.

Part of #4056.

Change-Id: Ie12512b492cd7d47a9e56ec3bc209f829feaf4b5
PiperOrigin-RevId: 177261295
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
index 664ea53..3758bdc 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
@@ -63,7 +63,6 @@
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
 import com.google.devtools.build.lib.skyframe.ExternalFilesHelper.ExternalFileAction;
 import com.google.devtools.build.lib.skyframe.PackageLookupFunction.CrossRepositoryLabelViolationStrategy;
-import com.google.devtools.build.lib.skyframe.PackageLookupValue.BuildFileName;
 import com.google.devtools.build.lib.skyframe.SkyframeActionExecutor.ActionCompletedReceiver;
 import com.google.devtools.build.lib.skyframe.SkyframeActionExecutor.ProgressSupplier;
 import com.google.devtools.build.lib.testutil.FoundationTestCase;
@@ -161,7 +160,11 @@
       final boolean keepGoing,
       @Nullable EvaluationProgressReceiver evaluationProgressReceiver) throws Exception {
     AtomicReference<PathPackageLocator> pkgLocator =
-        new AtomicReference<>(new PathPackageLocator(outputBase, ImmutableList.of(rootDirectory)));
+        new AtomicReference<>(
+            new PathPackageLocator(
+                outputBase,
+                ImmutableList.of(rootDirectory),
+                BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
     AtomicReference<TimestampGranularityMonitor> tsgmRef = new AtomicReference<>(tsgm);
     BlazeDirectories directories =
         new BlazeDirectories(
@@ -206,7 +209,7 @@
                     new PackageLookupFunction(
                         null,
                         CrossRepositoryLabelViolationStrategy.ERROR,
-                        ImmutableList.of(BuildFileName.BUILD_DOT_BAZEL, BuildFileName.BUILD)))
+                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY))
                 .put(
                     SkyFunctions.WORKSPACE_AST,
                     new WorkspaceASTFunction(TestRuleClassProvider.getRuleClassProvider()))
@@ -214,8 +217,11 @@
                     SkyFunctions.WORKSPACE_FILE,
                     new WorkspaceFileFunction(
                         TestRuleClassProvider.getRuleClassProvider(),
-                        TestConstants.PACKAGE_FACTORY_BUILDER_FACTORY_FOR_TESTING.builder().build(
-                            TestRuleClassProvider.getRuleClassProvider(), scratch.getFileSystem()),
+                        TestConstants.PACKAGE_FACTORY_BUILDER_FACTORY_FOR_TESTING
+                            .builder()
+                            .build(
+                                TestRuleClassProvider.getRuleClassProvider(),
+                                scratch.getFileSystem()),
                         directories))
                 .put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction())
                 .put(