Not all compilers nor compiler versions supports the attributes
used in OpenOCD code.
Collect in a single file the workaround to handle them.
Change-Id: I92d871337281169134ce8e40b2064591518be71f
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7519
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>