[freeglut] updated to 3.2.1

[isanych]

freeglut on master is not building with gcc 10, updated to latest version, fixed gcc 10 issues.

[isanych]

@NancyLi1013 done

[NancyLi1013]

LGTM, thanks for this PR @isanych .

[strega-nil]

@isanych what's up with the glut.h file? Shouldn't that be shipped with glut?

[isanych]

@strega-nil you right, it is still there, just has to be enabled

[strega-nil]

@isanych do you know what's wrong with x64_windows_static here? looks like a file rename failed with file not found?

[isanych]

@strega-nil with FREEGLUT_REPLACE_GLUT set both static and dynamic versions are called just glut and renaming is not needed anymore. vcpkg hopefully will be ok now, but to properly test unknown upstream changes it would be good to have small test project for each port which uses produced library - and if CI would build and run these binaries, it would give more confidence that changes are not breaking much.

For now it would be nice to get a notification with results when CI finish building.

[isanych]

looking at glui

[strega-nil]

Cool, thanks so much @isanych :)