Add JIT late override property

Required for JIT debug property since user builds can't restart
the shell.

Bug: 19735273

Change-Id: I1983852e80010c344b45e0bb459de47c56adfce8
diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java
index fced092..8674a21 100644
--- a/core/java/com/android/internal/os/Zygote.java
+++ b/core/java/com/android/internal/os/Zygote.java
@@ -34,10 +34,13 @@
     public static final int DEBUG_ENABLE_CHECKJNI   = 1 << 1;
     /** enable Java programming language "assert" statements */
     public static final int DEBUG_ENABLE_ASSERT     = 1 << 2;
-    /** disable the JIT compiler */
+    /** disable the AOT compiler and JIT */
     public static final int DEBUG_ENABLE_SAFEMODE   = 1 << 3;
     /** Enable logging of third-party JNI activity. */
     public static final int DEBUG_ENABLE_JNI_LOGGING = 1 << 4;
+    /** enable the JIT compiler */
+    public static final int DEBUG_ENABLE_JIT         = 1 << 5;
+
 
     /** No external storage should be mounted. */
     public static final int MOUNT_EXTERNAL_NONE = 0;