All the broken stuff just happened to work on 32-bit, but would cause
MinGW-w64 to explode if you tried building as 64-bit.
I guess thanks to Microsoft keeping the basic C int types the same
size in 64-bit as they were in 32-bit, this branch compiles as 64-bit
just fine, despite Cave Story's many int-size dependencies.
The filename is a total guess, but Microsoft's own word for these
menus is 'dialog', and these functions appear before the Draw.cpp
functions (the source files are linked alphabetically).