gh-136677: Introduce executable specific linker flags to configure (#137296)

* introduce executable specific linker flags

Add PY_CORE_EXE_LDFLAGS and EXE_LDFLAGS which stores executable specific
LDFLAGS, replacing PY_CORE_LDFLAGS for building
executable targets.

If PY_CORE_EXE_LDFLAGS / EXE_LDFLAGS is not provided, then it defaults
to the value of PY_CORE_LDFLAGS which is the existing behaviour.

If both flags are supplied, and there is a need
to distinguish between executable and shared specific LDFLAGS,
in particular, PY_CORE_LDFLAGS should contain the shared specific LDFLAGS.

* documentation for new linker flags

* update Misc folder documentation

* Update Makefile.pre.in

Co-authored-by: Victor Stinner <vstinner@python.org>

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Co-authored-by: Filipe Laíns <filipe.lains@gmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Filipe Laíns <lains@riseup.net>