jtreg, asmtools 7.0 b02

[Jonathan Gibbons]

Heads up, jtreg builders,

We need to update jtreg to use asmtools 7.0 b02. Although we don't 
normally recommend using early access versions of a release, it is 
necessary in this case to get support for recent new features required 
for testing JDK 11.

I will push the change to jtreg tip soon, and in due course will have  a 
new version tagged (and promoted internally).

-- Jon