Prepare D8 dexing tests for Java 11

Test was compiling `.class` files separately without any classes on classpath. As there where classes in nests that failed when compiled with Java 11.

Fixed by passing all input as classpath.

RELNOTES: None
PiperOrigin-RevId: 359464672

src/tools/android/java/com/google/devtools/build/android/r8/CompatDexBuilder.java

@@ -163,7 +163,7 @@ private void run(String[] args) throws IOException, InterruptedException, Execut
 
         List<Future<DexConsumer>> futures = new ArrayList<>(toDex.size());
         for (ZipEntry classEntry : toDex) {
-          futures.add(executor.submit(() -> dexEntry(zipFile, classEntry, executor)));
+          futures.add(executor.submit(() -> dexEntry(input, zipFile, classEntry, executor)));
         }
         for (int i = 0; i < futures.size(); i++) {
           ZipEntry entry = toDex.get(i);
@@ -176,11 +176,13 @@ private void run(String[] args) throws IOException, InterruptedException, Execut
     }
   }
 
-  private DexConsumer dexEntry(ZipFile zipFile, ZipEntry classEntry, ExecutorService executor)
+  private DexConsumer dexEntry(
+      String classpath, ZipFile zipFile, ZipEntry classEntry, ExecutorService executor)
       throws IOException, CompilationFailedException {
     DexConsumer consumer = new DexConsumer();
     D8Command.Builder builder = D8Command.builder();
     builder
+        .addClasspathFiles(Paths.get(classpath))
         .setProgramConsumer(consumer)
         .setMode(noLocals ? CompilationMode.RELEASE : CompilationMode.DEBUG)
         .setMinApiLevel(13) // H_MR2.