Add "for each" loop and c-style for loop

[some100]

The "for each" loop is a hidden block that basically acts as a repeat loop with a counter. It would set a variable to 1 and increment that variable each time the loop ran. This PR adds support for that kind of loop.
Additionally adds support for c-style for loop.

Syntax:
For Each

for x in n {
# code
}

C-style For

for x = 0; x > n; x++ {
#code
}

[aspizu]

Initially, my decision was to not add anything that generates hacked blocks, but it seems like the for block is popular demand due to its performance benefits. We will definitely use the in keyword in the implementation so need to think over the syntax. Come over to the discord to draft a RFC.

[aspizu]

I also have plans to add the C/JS/Java for(i = 0; i <10; i++) loop

[some100]

added "in" to for loop syntax. It might also be renamed "foreach" or "for each" to distinguish it from C-style loops should that be a future feature

[aspizu]

does this compile?

[some100]

yes (at least on my machine)

[aspizu]

could you implement #77?

[some100]

Added c-style loops, however there are a few issues with it

1. Statement 1 must be a variable assignment and it can't be a local or cloud. I couldn't find a good way to put in those two features.
2. The output code ends up incrementing the variable before the loop runs rather than after the loop runs. So i=0 ends up becoming in effect i=1.
3. Requires 3 semicolons, because the parser requires a semicolon in order to recognize something as a generic statement apparently

Syntax:

for x = 1; x > 10; x++; {
    #code
}

Output:

set x to 1
repeat until x > 10 {
    #code
    change x by 1
}

[aspizu]

3. that's because the { of the for loop's body is ambiguous to the { of a struct literal.

[some100]

issue 2 fixed, now behavior of for loop should be more consistent with other programming languages by incrementing after the loop runs

[some100]

should be fully working as expected now