On Windows this would fail because of missing DLL:
```
mylib = library(...)
exe = executable(..., link_with: mylib)
meson.add_install_script(exe)
```
The reason is on Windows we cannot rely on rpath to find libraries from
build directory, they are searched in $PATH. We already have all that
mechanism in place for custom_target() using ExecutableSerialisation
class, so reuse it for install/dist/postconf scripts too.
This has bonus side effect to also use exe_wrapper for those scripts.
Fixes: #8187
This patches takes the options work to it's logical conclusion: A single
flat dictionary of OptionKey: UserOptions. This allows us to simplify a
large number of cases, as we don't need to check if an option is in this
dict or that one (or any of 5 or 6, actually).
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082
Xavier Claessens
Antonin Décimo
Dylan Baker
Mathieu Duponchelle
Thibault Saunier