RFR: 8290981: Enable CDS for zero builds [v3]

[Ioi Lam]

> Enable CDS for zero builds. `java --version` is about 2x faster now.
> 
> 
> $ perf stat -r 40 ./images/jdk/bin/java -Xshare:off -version
> 0.034645 +- 0.000044 seconds time elapsed  ( +-  0.13% )
> $ perf stat -r 40 ./images/jdk/bin/java -version
> 0.018080 +- 0.000388 seconds time elapsed  ( +-  2.15% )
> 
> I also fixed a bug in Images.gmk that always wrote the default archive to $JAVA_HOME/lib/server. This fix also makes it possible for a client libjvm to have a default CDS archive.

Ioi Lam has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - @erikj79 comments; also fixed CDS test cases for zero
 - Merge branch 'master' into 8290981-enable-cds-for-zero
 - imported contribution by @shipilev - https://cr.openjdk.java.net/~shade/8290981/zero-cds-nofast-1.patch
 - create_cds_archive -> CreateCDSArchive
 - explicitly choose VM variant in create_cds_archive
 - clean up C code
 - 8290981: Enable CDS for zero builds

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9869/files
  - new: https://git.openjdk.org/jdk/pull/9869/files/004c5038..2716becb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9869&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9869&range=01-02

  Stats: 20828 lines in 932 files changed: 11978 ins; 5521 del; 3329 mod
  Patch: https://git.openjdk.org/jdk/pull/9869.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9869/head:pull/9869

PR: https://git.openjdk.org/jdk/pull/9869