font/shaper/harfbuzz: Update position logic to match recent CoreText changes

[jacobsandlund]

This PR incorporates the recent changes made to CoreText in the following PRs:

• font/coretext: Use positions to correct glyph placement #9883
• font/shaper: Fix CoreText position.y for some scripts #10179
• font/shaper/coretext: Detect ligatures to avoid positioning (marking) glyphs incorrectly #10295

Tests have been added verifying the behavior. Below are all the changes in shaping from the above PRs but now using HarfBuzz.

Tai Tham vowels (#9883)

Browser:

ᨯᩰ

Before:

(Note that this worked correctly with the old logic for HarfBuzz in contrast to CoreText)

After:

Tibetan characters (discussion #8054)

Browser:

ༀ

Before (with Noto Serif Tibetan):

After:

Tai Tham ligature (#10179 and #10295)

Browser:

ᩉ᩠ᨿᩩ

Before:

After:

Javanese ligature (#10295)

Browser:

ᩉ᩠ᨿᩩ

Before:

After:

Chakma ligature (#10295)

Browser:
𑄝𑄖𑄳𑄠𑄬

Before:

After:

Bengali ligature (#10295)

Browser:
রাষ্ট্রে

Before:

After:

Devanagari string (test changed in #10295)

Browser:
अपार्टमेंट

Before:

After:

AI disclaimer

I used Amp to copy the logic from CoreText, but had to help it along. I took over after I noticed the different behavior with HarfBuzz's default cluster level.

Adopt CoreText changes to HarfBuzz shaper
Rename debug_codepoints, explore HarfBuzz alternatives
Fix cluster indexing in codepoints array

[mitchellh]

Ran CI with some real failures!

[jacobsandlund]

Ah shoot, I thought it passed locally. I'll check tomorrow! Might be time for me to invest in a linux laptop

[jacobsandlund]

Okay, yeah, I confirmed running zig test -Dfont-backend=coretext_harfbuzz on my mac passes. I've been planning on getting a linux laptop for a while, so I think I'll do that now and then address the failures once I get it (making them pass on both linux and mac), instead of messing with a linux VM or partition. I'll mark this as draft for now.

[mitchellh]

I use a Linux VM on Mac to great success. Running tests you can do with any provider but running the GUI requires VMware due to OpenGL 4.3

[danielwe]

I can run the GUI no problem in my UTM/QEMU Linux VM on a mac host. Just select virtio-gpu-pci as GPU and install virtio drivers on the guest.

[jacobsandlund]

Okay, I'll look at running a linux VM on Tuesday!

[jacobsandlund]

Taking a bit to get set up on linux and also work's been busy. Maybe I'll be up and running tomorrow, if not early next week