WebKit upgrade

[Jarred-Sumner]

What does this PR do?

WIP.

JavaScriptCore functions on Windows now must use the (unix) SysV ABI

• All of our functions which are directly called from JavaScript must be changed to use the SysV ABI. In most cases in C++, there's not much to change. In Zig, many functions need to use callconv(JSC.conv) instead of callconv(.C). JSC.conv will do the right thing for the target platform.
• This change will break TinyCC (bun:ffi) on Windows. Still need to figure out what to do about this. Worst case: we add a wrapper function when used on Windows

Fixes #12084
Fixes #11667 (thanks to @Constellation)
#5970 does not fix that one

How did you verify your code works?

[github-actions]

clang-tidy nits are fixed! Thank you.

[github-actions]

❌ @Jarred-Sumner, your commit has failing tests :(

🪟💻 4 failing tests Windows x64 baseline

• test/cli/install/registry/bun-install-registry.test.ts 1 failing
• test/cli/install/registry/bun-install-windowsshim.test.ts code 1
• test/js/bun/shell/leak.test.ts 1 failing
• test/js/node/child_process/child_process.test.ts 1 failing

🪟💻 3 failing tests Windows x64

• test/cli/install/registry/bun-install-registry.test.ts 1 failing
• test/cli/install/registry/bun-install-windowsshim.test.ts code 1
• test/js/node/child_process/child_process.test.ts 1 failing

View logs

[dylan-conway]

Is it intentional some functions didn't have callconv(.C) replaced with callconv(JSC.conv) and only removed?