* push the arguments in reverse order
* add logic for pushing args of any abi size to stack - very similar to
`genSetStack` however, uses `.rsp` as the base register
* increment and decrement `.rsp` if we called a function with args on
the stack in `airCall`
* add logic for recovering args from the caller's stack in the callee
* implement `genSetStack` for `ptr_stack_offset`
* handle `ptr_add`
* implement storing from register into pointer in register
* split alignment and array tests into those that pass on x86_64 and
those that do not
* pass more tests on x86_64
* Fix backend using wrong union field of the slice instruction.
* LLVM backend properly sets alignment on global variables.
* Sema: add coercion for *T to *[1]T
* Sema: pointers to Decls with explicit alignment now have alignment
metadata in them.
Conflicts:
* doc/langref.html.in
* lib/std/enums.zig
* lib/std/fmt.zig
* lib/std/hash/auto_hash.zig
* lib/std/math.zig
* lib/std/mem.zig
* lib/std/meta.zig
* test/behavior/alignof.zig
* test/behavior/bitcast.zig
* test/behavior/bugs/1421.zig
* test/behavior/cast.zig
* test/behavior/ptrcast.zig
* test/behavior/type_info.zig
* test/behavior/vector.zig
Master branch added `try` to a bunch of testing function calls, and some
lines also had changed how to refer to the native architecture and other
`@import("builtin")` stuff.
