* instead of emitting a breakpoint for a debug safety crash,
zig calls a panic function which prints an error message
and a stack trace and then calls abort.
* on freestanding OS, this panic function has a default
implementation of a simple infinite loop.
* users can override the panic implementation by providing
`pub fn panic(message: []const u8) -> unreachable { }`
* workaround for LLVM segfaulting when you try to use cold
calling convention on ARM.
closes#245
* add `setFnTest`, `setFnVisible`, `setFnStaticEval`,
`setFnNoInline` builtin functions to replace previous
directive functionality
* add `coldcc` and `nakedcc` as keywords which can be used as part
of a function prototype.
* `setDebugSafety` builtin can be used to set debug safety features
at a per block scope level.
* closes#169
* Introduce the concept of packages. Closes#3
* Add support for error notes.
* Introduce `@import` and `@c_import` builtin functions and
remove the `import` and `c_import` top level declarations.
* Introduce the `use` top level declaration.
* Add `--check-unused` parameter to perform semantic
analysis and codegen on all top level declarations, not
just exported ones and ones referenced by exported ones.
* Delete the root export node and add `--library` argument.
* Directives can have arbitrary expressions as parameters
* Fix switch statement not generating code sometimes
* Rename "main" fn in bootstrap.zig to "zig_user_main" to
avoid name collisions
* codegen: fix badref when unreachable is last thing in an
expression
* support #condition directive on exported functions
