Add another case where cindent is correct

When calling a function, or anything with nested parens,
default to cindent's indent. The least error-prone way I
could think of identifying this is to look for a line
that ends with a ',', as well as a non-zero number of
any character except parens before the comma, and
then an open paren.

This will overlap with the previous rule accounting for
function definitions, but that should be fine because
it is also using cindent.
auto merge of #13600 : brandonw/rust/master, r=brson

When calling a function, or anything with nested parens,
default to cindent's indent. The least error-prone way I
could think of identifying this is to look for a line
that ends with a ',', as well as a non-zero number of
any character except parens before the comma, and
then an open paren.

This will overlap with the previous rule accounting for
function definitions, but that should be fine because
it is also using cindent.