RFR: 8253639: Change os::attempt_reserve_memory_at parameter order [v2]

[Stefan Karlsson]

> I propose that we change the parameter order from:
> os::attempt_reserve_memory_at(size, addr, <extra params>)
> 
> to:
> os::attempt_reserve_memory_at(addr, size, <extra params>)
> 
> This patch builds upon the changes in pull/357. There's currently no way to create an incremental review, but I want to
> get this out for review now. So, unfortunately you have to ignore the first commit and look at the second commit.

Stefan Karlsson has updated the pull request with a new target base due to a merge or a rebase. The pull request now
contains three commits:

 - Merge branch 'master' into 8253639_attempt_reserve_memory_param_order
 - 8253639: Change os::attempt_reserve_memory_at parameter order
 - 8253638: Cleanup os::reserve_memory and remove MAP_FIXED

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

Changes: https://git.openjdk.java.net/jdk/pull/359/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=359&range=01
  Stats: 27 lines in 10 files changed: 0 ins; 0 del; 27 mod
  Patch: https://git.openjdk.java.net/jdk/pull/359.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/359/head:pull/359

PR: https://git.openjdk.java.net/jdk/pull/359