RFR: 8319117: GrowableArray: Allow for custom initializer instead of copy constructor [v2]

[Johan Sjölen]

> Hi, 
> 
> When using at_put and at_put_grow you can provide a value which will be supplied to the constructor of each element. In other words, you can intialize each element through a copy constructor.
> 
> I suggest that we also provide a function equivalent where the function is provided a pointer to the memory to be initialized. This can be used for `NONCOPYABLE` classes, for example.
> 
> This is implemented using a SFINAE pattern because `nullptr` introduces ambiguity if you use static overload.
> 
> Currently running tier1-tier4.

Johan Sjölen has updated the pull request incrementally with two additional commits since the last revision:

 - Use variadic templates for in-place construction
 - Two tests

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16409/files
  - new: https://git.openjdk.org/jdk/pull/16409/files/579083ee..3e2c7a1e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16409&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16409&range=00-01

  Stats: 77 lines in 3 files changed: 44 ins; 27 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/16409.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16409/head:pull/16409

PR: https://git.openjdk.org/jdk/pull/16409