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/test/etc/run-test-jar b/test/etc/run-test-jar
index 28fa130..4214053 100755
--- a/test/etc/run-test-jar
+++ b/test/etc/run-test-jar
@@ -344,7 +344,7 @@
   else
     FLAGS="${FLAGS} -agentpath:${agent}=${TEST_NAME},art"
     FLAGS="${FLAGS} -Xplugin:${plugin}"
-    FLAGS="${FLAGS} -Xfully-deoptable"
+    FLAGS="${FLAGS} -Xcompiler-option --debuggable"
     # Always make the compilation be debuggable.
     COMPILE_FLAGS="${COMPILE_FLAGS} --debuggable"
   fi