[PATCH] elf: Drop elf/tls-macros.h in favor of __thread and tls_model attributes [BZ #28152] [BZ #28205]

[Joseph Myers]

On Wed, 11 Aug 2021, Fangrui Song via Libc-alpha wrote:

> As a future clean-up, TLS_LD/TLS_IE/TLS_IE macros can be removed from
> sysdeps/*/tls-macros.h. aarch64 TLS_GD definition should be retained to
> test traditional TLS GD while the toolchain default is TLSDESC.

It might be better to test different TLS dialects through the compiler 
generating appropriate code rather than keeping such macros around.  E.g., 
have a way for architectures to declare a set of supported -mtls-dialect= 
arguments (or detect them at configure time, at present there's a test for 
-mtls-dialect=gnu2 support), and, when more than one dialect is supported, 
run various tests explicitly for each dialect supported by the compiler, 
in addition to testing whatever the default dialect is.

-- 
Joseph S. Myers
joseph@codesourcery.com