Syntax highlighting for method definition as non-first parameter is broken #231

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: http://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: http://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
  • Checked that your issue isn't already filed: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aatom
  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

Syntax highlighting for method definition as non-first parameter is broken:

Steps to Reproduce

foo 'bar', def baz; end

Expected behavior: Method is highlighting as usual.

Actual behavior: Method's highlighting is broken.

Reproduces how often: 100%

Versions

$ atom --version
Atom    : 1.25.1
Electron: 1.7.11
Chrome  : 58.0.3029.110
Node    : 7.9.0

$ apm --version
apm  1.19.0
npm  3.10.10
node 6.9.5 x64
atom 1.25.1
python 2.7.14
git 2.17.0

Linux 4.15.15-1-ARCH