docs: update GL_ARB_copy_image, GL_ARB_clear_texture gallium status
docs: update GL_ARB_copy_image, GL_ARB_clear_texture gallium status

VMware is working on these.

Signed-off-by: Brian Paul <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@vmware.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler