RFR: 8260046: Assert left >= right in pointer_delta() methods [v2]

[Albert Mingkun Yang]

> Adding the assertion, and fixing a benign violation.
> 
> Test: tier1-7; no violation of this assertion.

Albert Mingkun Yang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - merge master
 - delta

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

Changes: https://git.openjdk.java.net/jdk/pull/3900/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3900&range=01
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3900.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3900/head:pull/3900

PR: https://git.openjdk.java.net/jdk/pull/3900