Provide mechanism to use "data" attribute in Bazel tests.

When supplying artifacts with "data" to Bazel tests, the file (for example tools/dir/file) is located in runfiles/sandbox at "../io_bazel/" (so in ../io_bazel/tools/dir/file). For purpose of mocking one needs to copy file from there to root dir (creating tools/dir/file).

PiperOrigin-RevId: 361126904
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
index 5a48234..ca980cc 100644
--- a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
+++ b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
@@ -67,6 +67,9 @@
   /** Location of the bazel repo relative to the workspace root */
   public static final String BAZEL_REPO_PATH = "";
 
+  /** The file path in which to create files so that they end up under Bazel main repository. */
+  public static final String BAZEL_REPO_SCRATCH = "../io_bazel/";
+
   /** Relative path to the {@code process-wrapper} tool. */
   public static final String PROCESS_WRAPPER_PATH =
       "io_bazel/src/main/tools/process-wrapper";