[BUGFIX] Allow C extension to be built in C90 mode
[BUGFIX] Allow C extension to be built in C90 mode

adhearsion/ruby_speech,adhearsion/ruby_speech,benlangfeld/ruby_speech,sfgeorge/ruby_speech,sfgeorge/ruby_speech,benlangfeld/ruby_speech,benlangfeld/ruby_speech,sfgeorge/ruby_speech,adhearsion/ruby_speech