RFR: 8255720: Optimize bci_to_dp/-data by enabling iteration over raw DataLayouts [v2]

[Claes Redestad]

> MethodData::bci_to_dp and ciMethodData::bci_to_data show up in startup/warmup profiles - much of the overhead allocating resource objects when iterating over ProfileData objects (next_data)
> 
> Providing a means to iterate over the raw DataLayout objects allow us to avoid explicitly allocating resource objects for purposes of calculating the next DataLayout address for the most common types. 
> 
> This patch reduces overhead of MethodData::bci_to_dp and ciMethodData::bci_to_data by 80% or more in profiles and has a measurable impact on simple startup tests, e.g. ~250k instruction (~0.2% of total) reduction on Hello World.
> 
> Testing: tier1-3 passed

Claes Redestad 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 six additional commits since the last revision:

 - More lines
 - Merge branch 'master' into bci_to_dp_opt
 - Merge branch 'master' into bci_to_dp_opt
 - Optimize bci_to_data in ciMethodData
 - Optimize bci_to_data similarly, remove dead code
 - Optimize bci_to_dp by enabling iteration over DataLayouts with as few allocations as possible

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/988/files
  - new: https://git.openjdk.java.net/jdk/pull/988/files/0d8e8f04..b12ff3b3

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=988&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=988&range=00-01

  Stats: 682 lines in 21 files changed: 593 ins; 37 del; 52 mod
  Patch: https://git.openjdk.java.net/jdk/pull/988.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/988/head:pull/988

PR: https://git.openjdk.java.net/jdk/pull/988