- Added null support in DynamicLibrary loading on non-Windows (dlopen(NULL) semantics), plus docs clarifying null is not supported on Windows.

[XavierMP14]

• Added null support in DynamicLibrary loading on non-Windows (dlopen(NULL) semantics), plus docs clarifying null is not supported on Windows.
• Added a new FFI benchmark benchmark/ffi/getpid.js using ffi.dlopen(null, ...) + uv_os_getpid. Thanks to @bengl for Foreign Function Interface (FFI) implementation nodejs/node#46905
• Documented new FFI error codes in doc/api/errors.md as asked from @jasnell in lib,src,test,doc: add node:ffi module nodejs/node#62072 (comment)
• Code documented behavior of why JS callback may abort the process. This address what requested by @jasnell in lib,src,test,doc: add node:ffi module nodejs/node#62072 (comment).

As promised to @justjake, also the following followups requested in nodejs/node#62072 (comment):

• Added ffi.exportArrayBuffer(...) and ffi.exportArrayBufferView(...).
• Added raw pointer helper ffi.getRawPointer(source) (Buffer | ArrayBuffer | ArrayBufferView), with strong “unsafe/dangerous” docs and tests.
• Moved byte-export copying to native code (exportBytes) to avoid extra JS Buffer wrapper allocations.

Originally posted by @ShogunPanda in nodejs/node#62762