RFR 8037082: java/lang/instrument/NativeMethodPrefixAgent.java failing

[Jaroslav Bachorik]

Please, review the following test fix.

Issue : https://bugs.openjdk.java.net/browse/JDK-8037082
Webrev: http://cr.openjdk.java.net/~jbachorik/8037082/webrev.00

As Staffan mentions in the issue comments - "The two tests 
NativeMethodPrefixAgent and RetransformAgent use their own byte code 
instrumentation library in jdk/test/java/lang/instrument/ilib/. These 
tests need to be rewritten to use ASM instead so that we don't have to 
maintain the ilib library."

This patch is intended to remove the "ilib" library and replace the 
usages with an ASM5 alternative. Only the currently used features of the 
"ilib" library are being ported.

Thanks,

-JB-