The purpose of this is:
* Only one way to do things
* Changing a function with void return type to return a possible
error becomes a 1 character change, subtly encouraging
people to use errors.
See #632
Here are some imperfect sed commands for performing this update:
remove arrow:
```
sed -i 's/\(\bfn\b.*\)-> /\1/g' $(find . -name "*.zig")
```
add void:
```
sed -i 's/\(\bfn\b.*\))\s*{/\1) void {/g' $(find ../ -name "*.zig")
```
Some cleanup may be necessary, but this should do the bulk of the work.
this reverts 5c04730534.
sadly the quality of the intel dialect in llvm's assembly
parser has many frustrating bugs, and generally has unfortunate
syntax.
the plan is to use AT&T for now since it at least works,
and eventually zig will have its own assembly parser for
x86 and it will be as close to NASM as possible.
Andrew Kelley