Suggested code improvement

[yonatan895]

I noticed that In the kernel.py file (in /tinygrad/codgen, line 49), a list is being created in memory while it doesn't have to be, like this:

for tc_dim in [i for i in range(2) if axes_exist[i]]

Why can't it just be with () instead of []:

for tc_dim in (i for i in range(2) if axes_exist[i])

I just went through the code from my phone and found it peculiar (although of course the performance diff is neglegble as there are only two runs)

[chenyu]

if you profile it and find significant diff in speed or mem usage we are happy to change, and would like to find a way to enforce it

often time it's negligible and python version dependent so not really worth it