RFR: 8328896: Fontmetrics for large Fonts has zero width

[Phil Race]

The main problem here is that we do not curate what font point size we passed to freetype,
and would pass in one larger than freetype's maximum of FT_USHORT_MAX which is USHRT_MAX.
This isn't documented, SFAICS, and is checked a couple of calls deep from the specific API we use.
But generally anywhere near that size seems to cause freetype to choke as it uses signed 16.16
values, so 32767 is really the max.
But we have no need to go anywhere near that - 16384 seems like a plenty large enough pt size.
And we can request bigger sizes than that by making use of the transform.
At normal size ranges we use that just to account for rotation and decompose the glyph transform
into point size and that rotation.

But at large sizes - which are not usefully rendered anyway - there are no hints etc to be lost
from not specifying the target point size. So we can extend the range of sizes we allow.

If  this is still too large to be held decomposed into a pt size in the range less than 16384 and a scale of up to 32766 then we substitute the null scaler, as we generally do when values are out of range, such
a for a NaN transform.

These extreme values aren't useful.

In looking at this I did find that getGlyphPixelBounds doesn't follow the maximum image size we use
for rendering. Which is not useful and could lead to inconsistent results. I fixed that.

Also whilst macOS didn't have these problems it could be cleaned up a bit for consistency in the reported sizes for some cases.

The test is mainly around making sure that "sensible" things are returned for not sensible input.
There's no 100% right answer to these extreme unrenderable sizes.

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Commit messages:
 - 8328896
 - 8328896
 - 8328896

Changes: https://git.openjdk.org/jdk/pull/18703/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18703&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328896
  Stats: 166 lines in 5 files changed: 164 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/18703.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18703/head:pull/18703

PR: https://git.openjdk.org/jdk/pull/18703