Vendors mimalloc sources and adds --enable-mimalloc as a mutually exclusive alternative to jemalloc, wiring it through mozalloc/mozglue and build config.
Since both gcc and clang support the internal __attribute__ form, and
this is guarded by HAVE_POSIX_MEMALIGN which is not a Windows thing,
it's safe to just use that attribute style unconditionally.
runtime expects.
Currently spams warnings but may actually error out if not fixed, or
result in undefined behaviour if mismatching signatures are treated as
redeclarations with different exception specifications.
We are using |throw(std::bad_alloc)|, but dynamic exception specifications have been deprecated in C++11. The C++11 equivalent is |noexcept(false)|. This causes build warning spam when using newer compilers such as GCC 7.x.