RFR: 8263771: Refactor javaClasses initialization code to isolate dumping code [v2]

[David Holmes]

> There is code in javaClasses that has a regular path and a CDS dump path. The latter is executed by the VMThread and can never throw exceptions, while the former can. If we refactor this we can simplify the exception management code. 
> 
> Testing: 
>  - runtime/cds locally
>  - tiers 1-3
> 
> Thanks,
> David

David Holmes has updated the pull request incrementally with one additional commit since the last revision:

  Renamed assertion checking function as suggested by Ioi

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3066/files
  - new: https://git.openjdk.java.net/jdk/pull/3066/files/d467c8da..197d199b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3066&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3066&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3066.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3066/head:pull/3066

PR: https://git.openjdk.java.net/jdk/pull/3066