RFR: Load coops base shift from AOTRuntimeConstants in AOT code [v4]

[Andrew Dinn]

> This PR modifies AOT compiled method code to load compressed oops base and shift constants via the AOTRuntimeConstants area rather than encode them as immediates. It also unlatches the currently forced setting of UseCompatibleCompressedOops, allowing the heap to be allocated wherever it will fit.

Andrew Dinn has updated the pull request incrementally with one additional commit since the last revision:

  fix oop decode not to side-effect flags

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

Changes:
  - all: https://git.openjdk.org/leyden/pull/20/files
  - new: https://git.openjdk.org/leyden/pull/20/files/243d72d5..7ba14a6e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=leyden&pr=20&range=03
 - incr: https://webrevs.openjdk.org/?repo=leyden&pr=20&range=02-03

  Stats: 12 lines in 1 file changed: 9 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/leyden/pull/20.diff
  Fetch: git fetch https://git.openjdk.org/leyden.git pull/20/head:pull/20

PR: https://git.openjdk.org/leyden/pull/20