Edge case for luamin and short-ifs
luamin collapses space between non-word characters and keywords. This is mostly correct except it breaks edge cases involving Pico-8's short-if. This feature is invisibly implemented by Pico-8 as a preprocessor replacement, and does not match the "if" if it has a non-word non-space character to its left.

````
x=true
y=(0)
if (x) y=1
print(y)
````

minifies to

````
x=true y=(0)if(x) y=1
print(y)
````

which would be correct if the "if" were expanded to its long form, but Pico-8 fails to expand it.

This works:

````
x=true y=(0)if(x) then y=1 end
print(y)
````

The workaround is to either avoid short-if, or to make sure that the previous line to a short-if ends in a word char.

luamin should either recognize short-if and preserve the leading space or just always preserve the leading space of the "if" keyword.