Redeclaration of a function* inside a block definition

Hi everyone,
I found a case of redeclaration of a generator function inside a block definition.

version: 1.11.19
OS: Linux Ubuntu 19.10 x64

steps to reproduce:

{
function* f() { yield 1 }
function f() { print(2) }
}
f()
Actual results:
2

Expected results:
SyntaxError: Identifier 'f' has already been declared

V8, SpiderMonkey works as expected.

cinfuzz