[PATCH] Use posix_fallocate instead of ftruncate.

[Joerg Sonnenberger via llvm-commits]

On Tue, Jul 19, 2016 at 10:06:31AM -0400, Rafael Espíndola via llvm-commits wrote:
> This makes sure that space is actually available. With this change
> running lld on a full file system causes it to exit with
> 
>  failed to open foo: No space left on device
> 
> instead of crashing with a sigbus.

I don't think that premise is correct. Writing can still fail, e.g. for
compressed file systems running low on space as well as file systems
with snapshotting or dedup.

Joerg