3fd8e7c77d
This allows `FLEX` to be linked statically to a binary that has `-Wstrict-prototypes` enabled (for example in CocoaPods without `use_frameworks!`. Changes: - Apply `void` to all the empty function/block declarations that don't take arguments. - Apply `SEL`/`UIImage *` to the others that actually take arguments. - Remove `CLANG_WARN_STRICT_PROTOTYPES = NO` since the default is enabled.