Conflicts:
 * lib/std/os/linux.zig
 * lib/std/os/windows/bits.zig
 * src/Module.zig
 * src/Sema.zig
 * test/stage2/test.zig

Mainly I wanted Jakub's new macOS code for respecting stack size, since
we now depend on it for debug builds able to pass one of the test cases
for recursive comptime function calls with `@setEvalBranchQuota`.

The conflicts were all trivial.