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: 360121530
diff --git a/src/tools/android/java/com/google/devtools/build/android/r8/CompatDexBuilder.java b/src/tools/android/java/com/google/devtools/build/android/r8/CompatDexBuilder.java
index 10be42b..dfa08a8 100644
--- a/src/tools/android/java/com/google/devtools/build/android/r8/CompatDexBuilder.java
+++ b/src/tools/android/java/com/google/devtools/build/android/r8/CompatDexBuilder.java
@@ -163,7 +163,7 @@
 
         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 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.