RFR: 8366456: Allow AllocFailStrategy for RBTree [v2]

[Johan Sjölen]

> Right now the RBTree forces you to use the intrusive tree if you want fine-grained control of the out-of-memory strategy of the node allocations. We can change this to be a bit more flexible.
> 
> One of the tests were incorrectly indented, so I fixed that. I also changed from `typedef` to `using`, turns out that `typedef` can give strange errors when the template instantiation is incorrect[0].
> 
> [0] For my particular gcc

Johan Sjölen has updated the pull request incrementally with one additional commit since the last revision:

  Remove

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27011/files
  - new: https://git.openjdk.org/jdk/pull/27011/files/8af9afc7..997e9592

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27011&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27011&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27011.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27011/head:pull/27011

PR: https://git.openjdk.org/jdk/pull/27011