RFR: 8335091: NMT: VMATree reserve_mapping and commit_mapping APIs need MEMFLAGS while un/-committing API has no MEMFLAGS arg [v5]

[Afshin Zafari]

> In committing a region, it is not mandatory to provide a MEMFLAGS flag where the committed region inherits the flag from the main region it resides in.
> In un-committing there is no need to a  MEMFLAGS at all. 
> The `register_mapping` API of the VMATree *requires* a MEMFLAGS (via metadata arg) in both of these two operations. To do the flag inheriting, it is possible to copy the flag of the left node in the tree to the newly inserted ones. 
> 
> An optional bool arg (default is false) is added to VMATree API to copy the existing flag of the left node to the new nodes.

Afshin Zafari has updated the pull request incrementally with two additional commits since the last revision:

 - fixed merge conflict
 - Johan's change set

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20330/files
  - new: https://git.openjdk.org/jdk/pull/20330/files/d9e36d51..c5978a03

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20330&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20330&range=03-04

  Stats: 152 lines in 3 files changed: 26 ins; 121 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/20330.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20330/head:pull/20330

PR: https://git.openjdk.org/jdk/pull/20330