I've had the same problem and oxillo's fix sorted it out. Thanks!
I found the file to modify was actually a .cpp rather than .c, but line 1016 was as described, and I modified it as instructed.
Presumably everyone who has tried to install 0.9.0 MSYS must have this problem? Perhaps a note in the MSYS guide is needed? Also, finding this post was not easy. Would a 'Installation Problems' category be useful?