RFR: 8293170: Improve encoding of the debuginfo nmethod section [v7]

[Boris Ulasevich]

> The nmethod "scopes data" section is 10% of the size of nmethod. Now the data is compressed using the Pack200 algorithm, which is good for encoding small integers (LineNumberTable, etc). Using the fact that half of the data in the partition contains zeros, I reduce its size by another 30%.
>  
> Testing: jtreg hotspot&jdk, Renaissance benchmarks

Boris Ulasevich 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 12 additional commits since the last revision:

 - adding jtreg test for CompressedSparseDataReadStream impl
 - align java impl to cpp impl
 - rewrite the SparseDataWriteStream not to use _curr_byte
 - introduce and call flush() excplicitly, add the gtest
 - minor renaming. adding encoding examples table
 - cleanup and rename
 - cleanup
 - rewrite code without virtual functions
 - warning fix and name fix
 - optimize the encoding
 - ... and 2 more: https://git.openjdk.org/jdk/compare/89c16176...637c94be

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/10025/files
  - new: https://git.openjdk.org/jdk/pull/10025/files/f365d780..637c94be

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10025&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10025&range=05-06

  Stats: 198377 lines in 2647 files changed: 114571 ins; 45710 del; 38096 mod
  Patch: https://git.openjdk.org/jdk/pull/10025.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10025/head:pull/10025

PR: https://git.openjdk.org/jdk/pull/10025