Output the precision for the return type in function declarations.

Tested with GLSL ES conformance suite (which doesn't test this) and
the WebGL conformance suite, which now contains tests to ensure that
these constructs compile correctly.

Chromium bug: http://crbug.com/86952
Review URL: http://codereview.appspot.com/4897045

git-svn-id: https://angleproject.googlecode.com/svn/trunk@731 736b8ea6-26fd-11df-bfd4-992fa37f6226
2 files changed