Please review: (JDK-8044866) Fix raw and unchecked lint warnings in asm

Hi Joe, all, Please approve fix for removings warnings in asm, this is merely a mini refresh from upstream sources, I have verified there are no more warnings in asm sources. http://cr.openjdk.java.net/~ksrini/8044866/webrev/ Thanks Kumar PS: many thanks to Remi Forax for pushing these fixes into the upstream source base.