Get all our k8 clang tools loading downloaded .sos

This is the last piece to make `bazel test //...` work on a barebones
Stretch system.

Change-Id: Ifa6d446dc6992cca35d4a333fb9bf6a10fddcd2e
diff --git a/tools/cpp/BUILD b/tools/cpp/BUILD
index bc094aa..3bee68e 100644
--- a/tools/cpp/BUILD
+++ b/tools/cpp/BUILD
@@ -71,6 +71,14 @@
 )
 
 filegroup(
+    name = "clang_3p6_strip_files",
+    srcs = [
+        "//tools/cpp/clang_3p6:strip",
+        "@clang_3p6_repo//:compiler_pieces",
+    ],
+)
+
+filegroup(
     name = "clang_3p6_compiler_files",
     srcs = [
         "//tools/cpp/clang_3p6:clang",
@@ -90,7 +98,7 @@
     linker_files = ":clang_3p6_linker_files",
     objcopy_files = "//tools/cpp/clang_3p6:objcopy",
     static_runtime_libs = [":empty"],
-    strip_files = "//tools/cpp/clang_3p6:strip",
+    strip_files = ":clang_3p6_strip_files",
     supports_param_files = 1,
 )