quantum depth 32 compile failure

Hi,

On behalf of the MacPorts project, I want to bring to your attention the fact that ImageMagick 6.6.9-9 doesn't compile with quantum depth 32. It compiles fine with quantum depth 8 or 16. The first error when compiling with quantum depth 32 is:

coders/png.c:12231:1: error: unterminated argument list invoking macro "SetRedPixelComponent"

Here's our full report:

https://trac.macports.org/ticket/29511