slice and array re-work plus some misc. changes

std.io.parseUnsigned buf parameter is const

fix crash on string literal with character code >= 128

rework compile-time known pointer values

zig logo in readme

remove the depends_on_compile_var code

lots of miscellaneous things all in one big commit

std.io supports printing integers as hex values

inline assembly allows clobbers with no input

variables, memcpy, and memset all get alignment

coldcc works better

improved behavior on debug safety crash

fix volatile not respected for storing through a struct pointer

fix assigning to const ptr through struct or index

try expression can omit variable assignments

tell LLVM the target sub arch type

use printf in test runner code

delete unneeded IR code and fix assigning to const ptr

fix volatile not respected for loads

all functions are nounwind because zig does not support exceptions

`%=` in inline assembly survives optimization

setGlobalSection and setGlobalAlign work for functions

even external functions which provide definitions get nounwind

infer hard float from target environments that imply it

memset and memcpy implementations need not return dest

inline assembly supports `%=` syntax

memcpy and memset builtins support volatile pointers

remove volatileStore builtin; add volatile pointers

add compile error when setting non power of 2 alignment

ability to set global variable alignment and ...

preserve names of exported variables

in freestanding environment, assume gnu binutils

add volatileStore() builtin function

add setGlobalAlign and setGlobalSection builtin functions

add ability to set linker script

typedefs work for binary math operations

exported global variables get emitted as external in LLVM

implement packed structs

make --target-os freestanding work

update outdated comment

add try expression

fix ability to call method on variable at compile time

fix behavior when initializing struct with undefined

remove ability to mark if and switch as inline

prefix op maybe and error are for types only

document setDebugSafety builtin function

fix var args allocating wrong amount of memory in compiler

fix crash when passing void to var args function

add integer literal to pointer explicit cast

readme update

fix crash when assigning too large value to integer

fix compile time initialization of array with undefined

fix sometimes using wrong outer scope for generating defers

fix behavior for comptime and runtime basic block phi

fix runtime branching tricking the comptime evaluation

update cat example code

printf var args proof of concept

various fixes

basic support for functions with variable length arguments

update charToDigit to take advantage of switch syntax

mem.free no longer requires explicit type argument

remove staticEval builtin in favor of comptime expression

introduce comptime expression

use comptime instead of inline for var and params

get rid of zeroes literal

add test for compile error returning from defer expression

add test for compile time bool not operator

ability to equality compare with null

equality comparison of void types is known at compile time

implement error when assigning to field of const struct

add test for short-circuit AND and OR assignment

Merge branch 'master' into ir-merge

fix handling of const values for 2d arrays

fix array of enums. also render debug info for const vars

fix get_maybe_type not ensuring complete child type

fix llvm assertion failure for zero bits structs

fix handling of invalid enumeration

fix enum codegen and implement comptime switch var on enums

fix some stuff when llvm has assertions on

fix some bugs with structs

fix crash when casting fn call arg

fix use decl regression

IR: fix array concatenation

IR: implement macro for function aliasing function pointer

pass some parseh tests

pass more tests

fix some tests

better error message for unable to eval const expr

fix a few tests

IR: implement error for missing or extra switch prongs

partially fix parseh command

pass division by zero test

pass unnecessary if statement test

fix unable to eval const expr test case

fix some tests

don't try to eval extern functions at compile time

pass conflicting variable name test

add compile error for initializing struct with non struct type

don't mark call instruction as generated

pass more tests