mishoo/UglifyJS v3.16.3 on GitHub

improve elimination of return statements (0207b46, c8d98f4)
merge common tail of if statements (d89f096, 3dcf098, 902292f, b92a89f)
improve compression of non-trivial function parameters (154edf0, 24443b6, b371dc2)
support import & export of non-ECMAScript identifiers (d67daa8)

assignment operator (5792f30, f0120e9)
default parameter (ec4558b)
export statement (b2bc2e1)
import() (0b808f6)
import.meta (0b808f6)
import statement (b2bc2e1)
rest parameter (38bd4f6)
spread syntax (56e9454)