Consistently place C++ use of extern "C" after all include directives,
within the negative branch of _ASMLANGUAGE if used.
Background from issue #17997:
Declarations that use C linkage should be placed within extern "C"
so the language linkage is correct when the header is included by
a C++ compiler.
Similarly #include directives should be outside the extern "C" to
ensure the language-specific default linkage is applied to any
declarations provided by the included header.
See: https://en.cppreference.com/w/cpp/language/language_linkage
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
move sys_io.h to sys/sys_io.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
We had architectures doing this differently, some had a dedicated
sys_io.h file, some not. Unify how it is done by splitting the arch
specific sys_io implementation into a sys_io file and include it
instead.
Move bits_portable.h to arch/common and split the file so more
architecture can reuse some of the definitions here instead of
duplicating code.
Where applicable use the common sys_io/ffs definitions.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
