[singlejar] Port test_util to Windows

- Port various functions in `test_util` to Windows.
- Change `@local_jdk//:jdk-default` (target does not seem to exist) to `@local_jdk//:jdk`.

See #2241

Closes #6248.

PiperOrigin-RevId: 217138180
diff --git a/tools/BUILD b/tools/BUILD
index 684b5d4..c9ffaf5 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -20,7 +20,6 @@
         "//tools/platforms:srcs",
         "//tools/genrule:srcs",
         "//tools/cpp:srcs",
-        "//tools/cpp/runfiles:srcs",
         "//tools/j2objc:srcs",
         "//tools/objc:srcs",
         "//tools/osx:srcs",
@@ -45,8 +44,7 @@
         "//tools/build_rules:embedded_tools_srcs",
         "//tools/buildstamp:srcs",
         "//tools/coverage:srcs",
-        "//tools/cpp:srcs",
-        "//tools/cpp/runfiles:embedded_tools",
+        "//tools/cpp:embedded_tools",
         "//tools/genrule:srcs",
         "//tools/java:embedded_tools",
         "//tools/j2objc:srcs",