Bun were so excited about their 4x speed improvement that they missed that Zig had already implemented it, plus other optimisations that were far larger.
Nothing in your link supports this assertion. Lots of things in your link support the exact opposite in fact, that the Bun team explicitly chose not to attempt to upstream the changes.
Nothing in your link supports this assertion. Lots of things in your link support the exact opposite in fact, that the Bun team explicitly chose not to attempt to upstream the changes.