Formatting: assignment to @method call shouldn't break

[helixbass]

With indentChain: false, this is formatting like this:

aaaaaaaaa =
  @cacheToCodeFragments step.cache o, LEVEL_LIST, shouldCache

but should presumably be nicer like this:

aaaaaaaaa = @cacheToCodeFragments(
  ...
)

This seems to get a little bit into isChainableCall() - should sniff around that wrt #111's changes