Previously, std.debug.assert would `@panic` in test builds,
if the assertion failed. Now, it's always `unreachable`.
This makes release mode test builds more accurately test
the actual code that will be run.
However this requires tests to call `std.testing.expect`
rather than `std.debug.assert` to make sure output is correct.
Here is the explanation of when to use either one, copied from
the assert doc comments:
Inside a test block, it is best to use the `std.testing` module
rather than assert, because assert may not detect a test failure
in ReleaseFast and ReleaseSafe mode. Outside of a test block, assert
is the correct function to use.
closes#1304
It's needed because LLVM emits library calls to compiler-rt when hardware lacks
functionality, for example, 64-bit integer multiplication on 32-bit x86.
This library is automatically built as-needed for the compilation target and
then statically linked and therefore is a transparent dependency for the
programmer.
Any bugs should be solved by trying to duplicate the bug upstream.
If the bug exists upstream, get it fixed with the LLVM team and then port
the fix downstream to Zig.
If the bug only exists in Zig, something went wrong porting the code,
and you can run the C code and Zig code side by side in a debugger
to figure out what's happening differently.