Expose Blob as a global

[Jamesernator]

What is the problem this feature will solve?

Increase parity with web APIs. In particular allowing interfaces to more generally associate a content type with a chunk of data in a portable way (leaving it up to the host how the data is actually stored).

And while APIs could accept blobs without having the global, one can't do checks like value instanceof Blob (i.e. in cases where an API accepts other kinds of objects), or construct blobs directly using the constructor.

What is the feature you are proposing to solve the problem?

Expose buffer.Blob as a global Blob like is on the web.

I am not proposing changing the experimental status however.

What alternatives have you considered?

No response

[aduh95]

Fixed by #41270, should land in v18.0.0 scheduled for April.

FWIW adding now globals is considered a breaking change and therefore is not backported to LTS lines – in case some code out there is using this kind of pattern:

if (!globalThis.Blob) {
  // Node.js only code here
}