RFR: 8267095: Miscellaneous cleanups in vm.runtime.defmeth tests [v4]

[Vladimir Ivanov]

> Miscellaneous refactorings/cleanups in `vm.runtime.defmeth` tests.
> 
> In particular: 
>   - replace `test/hotspot/jtreg/vmTestbase/vm/runtime/defmeth/scenarios` with enumeration of different test configurations in tests themselves; 
>   - pass `TestBuilder` as a parameter and initiate test execution from executor; 
>   - switch max class file version tested from 52 to 61 (`V17`); 
>   - minor changes (cleanups, new test cases)
> 
> Testing:
> - [x] vmTestbase/vm/runtime/defmeth/
> - [x] hs-tier5-rt - hs-tier8-rt

Vladimir Ivanov has updated the pull request incrementally with one additional commit since the last revision:

  Improve README

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4008/files
  - new: https://git.openjdk.java.net/jdk/pull/4008/files/bcba4283..66cda654

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4008&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4008&range=02-03

  Stats: 19 lines in 1 file changed: 19 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4008.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4008/head:pull/4008

PR: https://git.openjdk.java.net/jdk/pull/4008