Update D8 and R8 to 1.4.20-dev

Version: master 8f8dc1176f7de29e2d885d459703c3f52228665c
This build IS NOT suitable for preview or public release.

Built here: go/r8-releases/raw/master/8f8dc1176f7de29e2d885d459703c3f52228665c

Test: m -j PRODUCT-aosp_arm64-eng core-oj
Change-Id: I793caf9ce7a76f58eb7915416bede4eba9578168
diff --git a/d8.bat b/d8.bat
index 43f6bf4..32f914f 100644
--- a/d8.bat
+++ b/d8.bat
@@ -84,5 +84,5 @@
 :endArgs
 
 set javaOpts=%javaOpts% %defaultXmx% %defaultXss%
-call "%java_exe%" %javaOpts% -Djava.ext.dirs="%frameworkdir%" -jar "%jarpath%" %params%
+call "%java_exe%" %javaOpts% -Djava.ext.dirs="%frameworkdir%" -cp "%jarpath%" com.android.tools.r8.D8 %params%