Function gl::CopyTexImage2D

pub unsafe fn CopyTexImage2D(
    target: GLenum, 
    level: GLint, 
    internalformat: GLenum, 
    x: GLint, 
    y: GLint, 
    width: GLsizei, 
    height: GLsizei, 
    border: GLint
)

Fallbacks: CopyTexImage2DEXT