libroot/glibc: apply upstream fix for printf_fphex: Fix up long double fphex.

https://github.com/bminor/glibc/commit/a53b7a4e4b39d90f5964841c63492cf233aa17b8
fix #18353

libroot/stdio: Use the proper macros for isnan/isinf.

glibc/stdio-common: Use public functions vs private

Change-Id: Ide788b0edb15852e6315b0d5e9208cb3555cf4db
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2125
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

Change all references to "__INTEL__" to "__i386__".

They are functionally identical, but the former is a BeOS/Haiku-specfic
macro that we include in the compiler specs, and the latter is defined
by GCC.

Fix #9928: broken printf specifiers "%La" and "%LA"

* fix unitialized variables in __printf_fphex() in case of architectures
without support for long double - this triggered unreliable results
or crashes when using %La or %La on x86
* activate long double implementation in use for x86_64 for x86, too,
as they share the long double format
(cherry picked from commit d1716b277cbaf2b4265728d559b819d73330c1ef)

Fix #9928: broken printf specifiers "%La" and "%LA"

* fix unitialized variables in __printf_fphex() in case of architectures
without support for long double - this triggered unreliable results
or crashes when using %La or %La on x86
* activate long double implementation in use for x86_64 for x86, too,
as they share the long double format

More x86_64 printf() fixes from glibc.

Renamed src/kernel to src/system.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12359 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fix #9928: broken printf specifiers "%La" and "%LA"

* fix unitialized variables in __printf_fphex() in case of architectures
without support for long double - this triggered unreliable results
or crashes when using %La or %La on x86
* activate long double implementation in use for x86_64 for x86, too,
as they share the long double format
(cherry picked from commit d1716b277cbaf2b4265728d559b819d73330c1ef)

Fix #9928: broken printf specifiers "%La" and "%LA"

* fix unitialized variables in __printf_fphex() in case of architectures
without support for long double - this triggered unreliable results
or crashes when using %La or %La on x86
* activate long double implementation in use for x86_64 for x86, too,
as they share the long double format

More x86_64 printf() fixes from glibc.

Renamed src/kernel to src/system.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12359 a95241bf-73f2-0310-859d-f6bbb57e9c96