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
With C/C++, on Windows you don't need to pass any arguments for a static
library to be PIC. On UNIX platforms you need to pass -fPIC.
Other languages such as D have compiler-specific PIC arguments required
for PIC support in static libraries on UNIX platforms.
This kwarg allows people to specify which static libraries should be
built with PIC support. This is usually used for static libraries that
will be linked into shared libraries.