Adding Bazel aspect to enumerate output files of specified targets along with their maven pseudo-coordinates.

Change-Id: I68e6856be0c2afeac32c1dee5c2eca0c1bb81481
diff --git a/tools/build/bazel/print_mvn_jar.bzl b/tools/build/bazel/print_mvn_jar.bzl
new file mode 100644
index 0000000..8e183c22
--- /dev/null
+++ b/tools/build/bazel/print_mvn_jar.bzl
@@ -0,0 +1,14 @@
+load("//tools/build/bazel:generate_workspace.bzl", "maven_coordinates")
+
+# Example invocation:
+# bazel build $(bazel query 'kind("_bnd rule", //...)') \
+#       --aspects tools/build/bazel/mvn_jar.bzl%print_mvn_jar 2>&1 | \
+#     egrep "DEBUG: .*mvn_jar.bzl" | cut -d\  -f3-
+
+def _impl(target, ctx):
+    [ print (maven_coordinates(target.label), f.path) for f in target.files ]
+    return []
+
+print_mvn_jar = aspect(
+    implementation = _impl,
+)