Add new bindings generator; port SSLConfig (#23169)

Add a new generator for JS → Zig bindings. The bulk of the conversion is
done in C++, after which the data is transformed into an FFI-safe
representation, passed to Zig, and then finally transformed into
idiomatic Zig types.

In its current form, the new bindings generator supports:

* Signed and unsigned integers
* Floats (plus a “finite” variant that disallows NaN and infinities)
* Strings
* ArrayBuffer (accepts ArrayBuffer, TypedArray, or DataView)
* Blob
* Optional types
* Nullable types (allows null, whereas Optional only allows undefined)
* Arrays
* User-defined string enumerations
* User-defined unions (fields can optionally be named to provide a
better experience in Zig)
* Null and undefined, for use in unions (can more efficiently represent
optional/nullable unions than wrapping a union in an optional)
* User-defined dictionaries (arbitrary key-value pairs; expects a JS
object and parses it into a struct)
* Default values for dictionary members
* Alternative names for dictionary members (e.g., to support both
`serverName` and `servername` without taking up twice the space)
* Descriptive error messages
* Automatic `fromJS` functions in Zig for dictionaries
* Automatic `deinit` functions for the generated Zig types

Although this bindings generator has many features not present in
`bindgen.ts`, it does not yet implement all of `bindgen.ts`'s
functionality, so for the time being, it has been named `bindgenv2`, and
its configuration is specified in `.bindv2.ts` files. Once all
`bindgen.ts`'s functionality has been incorporated, it will be renamed.

This PR ports `SSLConfig` to use the new bindings generator; see
`SSLConfig.bindv2.ts`.

(For internal tracking: fixes STAB-1319, STAB-1322, STAB-1323,
STAB-1324)

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Alistair Smith <hi@alistair.sh>

cmake/Options.cmake

@@ -202,4 +202,9 @@ optionx(USE_WEBKIT_ICU BOOL "Use the ICU libraries from WebKit" DEFAULT ${DEFAUL
 
 optionx(ERROR_LIMIT STRING "Maximum number of errors to show when compiling C++ code" DEFAULT "100")
 
+# This is not an `option` because setting this variable to OFF is experimental
+# and unsupported. This replaces the `use_mimalloc` variable previously in
+# bun.zig, and enables C++ code to also be aware of the option.
+set(USE_MIMALLOC_AS_DEFAULT_ALLOCATOR ON)
+
 list(APPEND CMAKE_ARGS -DCMAKE_EXPORT_COMPILE_COMMANDS=ON)