Introducing the Java compilation black box in Skylark.

Adding a new declared provider that will be the returning value of the Java compilation method in Skylark. This provider is considered a black-box from Skylark and it should only be passed around (returned from a rule/aspect implementation) to allow Java rules to depend on it.

Also adding a new Skylark module (java_common) to allow retrieving the Java dependencies' black-box from Skylark implementations.

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MOS_MIGRATED_REVID=140138446
diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 47e35ea..9fadf7f 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -895,6 +895,7 @@
         "//src/main/java/com/google/devtools/build/lib:bazel-main",
         "//src/main/java/com/google/devtools/build/lib:bazel-rules",
         "//src/main/java/com/google/devtools/build/lib:build-base",
+        "//src/main/java/com/google/devtools/build/lib:collect",
         "//src/main/java/com/google/devtools/build/lib:java-compilation",
         "//src/main/java/com/google/devtools/build/lib:java-rules",
         "//src/main/java/com/google/devtools/build/lib:packages-internal",