RCR 316: arguments after a splat in a method call

The restriction that no arguments or splats follow a splat when calling a method should be removed. The same can be said of the multiple-assign RHS.

Many times, you'll want to splat some array in an argument list into its components. This need may or may not correlate to where a splatted (or maybe unsplatted?) argument is in the method definition. Currently, if you want to do something like this:

a,b,*c,d,*f,g

you have to do this:

a,b,*(c+[d]+f+[g])

A calling argument list or RHS of a multiple-assign like this:

a, *b, c, d, *e, f

should be equivalent to:

*([a]+b+[c]+[d]+e+[f])

Basically, form an array by concatenating arguments as elements (not splatted) or as arrays (splatted). Then splat the whole thing as the argument list.

The current limitation that no arguments are allowed after a splatted argument within an argument list seems quite arbitrary.

No backwards incompatibilities.

I just found that this legacy RCR is almost identical:

https://rcrchive.net/rcr/show/115

A parser change and more continuity in how calling argument lists (and MRHS) are handled.