release/18.x branch, commit 78b99c73ee4b96fe9ce0e294d4632326afb2db42
This adds the flag `-D_LIBCPP_HARDENING_MODE` which is determined based
on the Zig optimization mode.
This commit also fixes libunwind, libcxx, and libcxxabi to properly
report sub compilation errors.
release/17.x branch, commit 8f4dd44097c9ae25dd203d5ac87f3b48f854bba8
This adds the flag `-D_LIBCPP_PSTL_CPU_BACKEND_SERIAL`. A future
enhancement could possibly pass something different if there is a
compelling parallel implementation. That libdispatch one might be worth
looking into.