Make --debuggable rely on JIT code.

Removes -Xfully-deoptable in the process, which was added as a
temporary workaround until this CL.
Partial revert of https://android-review.googlesource.com/#/c/302232/

Makes things consistent with existing infrastructure:

- Parse the --debuggable from the compiler options, just like
  --compiler-filter.

- Add DEBUG_JAVA_DEBUGGABLE, passed by the zygote, for debuggable apps.

- Java debuggable now solely relies on JIT for simplicity.

- Debugging under userdebug for non-java-debuggable apps is still
  best effort.

Test: test-art-host, jdwp

bug: 28769520
Change-Id: Id0593aacd85b9780da97f20914a50943957c858f
diff --git a/runtime/oat_file_assistant.cc b/runtime/oat_file_assistant.cc
index 8554fa2..b19ace5 100644
--- a/runtime/oat_file_assistant.cc
+++ b/runtime/oat_file_assistant.cc
@@ -530,7 +530,7 @@
     class_path = OatFile::kSpecialSharedLibrary;
   }
   argv.push_back(class_path);
-  if (runtime->IsDebuggable()) {
+  if (runtime->IsJavaDebuggable()) {
     argv.push_back("--debuggable");
   }
   runtime->AddCurrentRuntimeFeaturesAsDex2OatArguments(&argv);