[master] RFR: Load Klass* from header in interpreter (x86) [v2]

[Roman Kennke]

> This implements loading the compressed Klass* from the object header, instead of the Klass* field in the x86 interpreter. It does the fast-path (unlocked object) in assembly, and calls into the runtime to deal with locked objects.
> 
> Testing:
>  - [x] tier1
>  - [x] tier2
>  - [x] hotspot_gc

Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:

  Update comment about xorb/xorq encoding

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

Changes:
  - all: https://git.openjdk.java.net/lilliput/pull/15/files
  - new: https://git.openjdk.java.net/lilliput/pull/15/files/444464a1..99f9a36b

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=lilliput&pr=15&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=lilliput&pr=15&range=00-01

  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/lilliput/pull/15.diff
  Fetch: git fetch https://git.openjdk.java.net/lilliput pull/15/head:pull/15

PR: https://git.openjdk.java.net/lilliput/pull/15