local consts with comptime init exprs

```zig
export fn entry() void {
    const x = if (true) u8(4) else u32(8);
}
```

```llvm
define void @entry() #2 !dbg !35 {
Entry:
  call void @llvm.dbg.declare(metadata i8* @0, metadata !39, metadata !DIExpression()), !dbg !41
  ret void, !dbg !42
}
```
3702c278e3Andrew Kelley committed on 5/31/2019, 4:22:12 AMparent95d9835
1 file changedLine totals unavailable