Before this commit, definitions of error codes must match a strict pattern,
with a Doxygen comment following the definition on the same line and
starting with "/**<". Change how generate_errors.pl so that the Doxygen
comment can be before the definition instead of after, and doesn't have to
be on the same line.
Also allow spaces between "#" and "define", and allow Doxygen comments to
start with "/*!" rather than "/**". Starting with "///" or "//!" is not
supported.
This commit does not change the output of generate_errors.pl.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>