Make the include guards consistent by renaming them systematically according
to the naming conventions below
For the public header files (in the 'include/openssl' directory), the guard
names try to match the path specified in the include directives, with
all letters converted to upper case and '/' and '.' replaced by '_'. For the
private header files files, an extra 'OSSL_' is added as prefix.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9333)
Apart from ssltest_old.c, the test suite relied on e_os.h for the
OSSL_NELEM macro and nothing else.
The ssltest_old.c also requires EXIT and some socket macros.
Create a new header to define the OSSL_NELEM macro and use that instead.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4186)
