* add runtime safety for slicing pointers, arrays, and slices.
* slicing without a sentinel value results in non-sentineled slice
* improved `std.debug.panic` handling of panic-during-panic
This change was mostly made with `zig fmt` and this also modified some whitespace. Note that in some files, `zig fmt` produced incorrect code, so the change was made manually.
* Implements #3768. This is a sweeping breaking change that requires
many (trivial) edits to Zig source code. Array values no longer
coerced to slices; however one may use `&` to obtain a reference to
an array value, which may then be coerced to a slice.
* Adds `IrInstruction::dump`, for debugging purposes. It's useful to
call to inspect the instruction when debugging Zig IR.
* Fixes bugs with result location semantics. See the new behavior test
cases, and compile error test cases.
* Fixes bugs with `@typeInfo` not properly resolving const values.
* Behavior tests are passing but std lib tests are not yet. There
is more work to do before merging this branch.
Thanks to the Windows Process Environment Block, it is possible to
obtain handles to the standard input, output, and error streams without
possibility of failure.
It had the downside of running all the comptime blocks and resolving
all the usingnamespaces of each system, when just trying to discover if
the current system is a particular one.
For Darwin, where it's nice to use `std.Target.current.isDarwin()`, this
demonstrates the utility that #425 would provide.
