RFR: 8335701: Make GrowableArray templated by an Index

[Johan Sjölen]

Hi,

Today the GrowableArray has a set index type of `int`, this PR makes it so that you can set your own index type through a template parameter.

This opens up for a few new design choices:

- Do you know that you have a very small array? Use an `uint8_t` for len and cap, each.
- Do you have a very large one? Use an `uint64_t`.

The code has opted for `int` being default, as to keep identical semantics for all existing code and to let users not have to worry about the index if they don't care.

One "major" change that I don't want to get lost in the review: I've changed the mid-point calculation to be overflow insensitive without casting.



// Old 
mid = ((max + min) / 2);
// New
mid = min + ((max - min) / 2);

Some semi-rigorous thinking:
min \in [0, len)
max \in [0, len)
min <= max
max - min / 2 \in [0, len/2)
Maximizing min and max => len + 0
Maximizing max, minimizing min => len/2
Minimizing max, maximizing min => max = min => min


// Proof that they're identical when m, h, l \in N
(1) m = l + (h - l) / 2 <=>
2m = 2l + h - l = h + l

(2) m = (h + l) / 2 <=>
2m = h + l
(1) = (2)
QED

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

Commit messages:
 - Fix spelling and actually include the growableArray is it used in cpp file
 - Move
 - Handle unhandled oops
 - Make GrowableArray receive an Index type optionally

Changes: https://git.openjdk.org/jdk/pull/20031/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20031&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335701
  Stats: 262 lines in 32 files changed: 19 ins; 25 del; 218 mod
  Patch: https://git.openjdk.org/jdk/pull/20031.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20031/head:pull/20031

PR: https://git.openjdk.org/jdk/pull/20031