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
* zig fmt
* std.mem.join takes a slice of slices instead of var args
* std.mem.join takes a separator slice rather than byte,
and always inserts it. Previously it would not insert the separator
if there already was one, violating the documented behavior.
* std.mem.join calculates exactly the correct amount to allocate
and has no call to allocator.shrink()
* bring back joinWindows and joinPosix and the corresponding tests.
it is intended to be able to call these functions from any OS.
* rename std.os.path.resolveSlice to resolve (now resolve takes
a slice of slices instead of var args)
init-lib creates a working static library with tests, and
init-exe creates a working hello world with a `run` target.
both now have test coverage with the new "cli tests" file.
closes#1035
