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
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
Fortran: check for undeclared variables by forcing implicit none everywhere
C/C++: check for unused parameters and return types
removed unused variables from test cases
ci: do missing return and unused arg check with Github Actions