Fixes#10539 in a diplomatic way (as opposed to telling Gentoo users
to just change their distro or rebuild zlib from upstream...).
(cherry picked from commit 67e6c1b735)
Godot-specific changes are undone in this commit, they will be readded
and properly documented in the following commit.
(cherry picked from commit 5681b7b60a)
This avoids namespace collisions with things such as X509_NAME.
Also force include of necessary definitions in `crypto/o_str.c`
which seem missing on MSVC (but work on MinGW).
(cherry picked from commit c1b0662b40)
Our necessary custom changes will be reapplied in later commits for clarity,
and saved as patches for future updates.
(cherry picked from commit cb0f771aaa)