feat: add PYBIND11_NOINLINE_ATTR and PYBIND11_INLINE macros

Decompose PYBIND11_NOINLINE into the attribute part plus inline, and
add PYBIND11_INLINE, which becomes empty under PYBIND11_PRECOMPILED.
Groundwork for optional pre-compilation; all current expansions are
unchanged and PYBIND11_INLINE is not used yet.

Assisted-by: ClaudeCode:claude-fable-5
1 file changed