Add C++ rules loads to Bazel tests

PiperOrigin-RevId: 833306958
Change-Id: I882ab5c7babafd2832c72a31fca186b4056218d1

Author: comius

src/test/java/com/google/devtools/build/lib/packages/BUILD

@@ -152,6 +152,7 @@ java_library(
         "//tools/python:srcs",  # For BazelMockPythonSupport
         "@rules_cc//cc:srcs",
         "@rules_cc//cc/common:srcs",
+        "@rules_cc//cc/private:srcs",
         "@rules_cc//cc/toolchains:srcs",
     ],
     deps = [