Requesting code review for JDK-8008199 - lazy jitting/Trampoline work

[Marcus Lagergren]

Enhancement: https://jbs.oracle.com/bugs/browse/JDK-8008199

With the experimental -Dnashorn.compiler.lazy flag, we will only jit the script by default, and create trampolines for all inner functions, causing them to be generated and executed upon first call. No type specialization yet and no intelligent picking and choosing candidates. Every lazy function will appear in a new CompileUnit of its own when the trampoline hits. Infrastructure is in place, but additional CRs will be filed to something cool with this. Disabled by default.

Webrev: 
http://cr.openjdk.java.net/~lagergren/8008199/