MSVC: Fix SID

[lukas-w]

Fixes SID for MSVC by using the provided working buffer instead of a local one to avoid the use of VLA. Changed the loop to go backwards to avoid overwriting data in the short-to-float conversion. Hope this logic is correct (it appears to sound right).

[PhysSong]

Nice trick! However, I think you should add a comment that describes the reason for your change.

[tresf]

I think you should add a comment that describes the reason for your change.

They were obvious, so I just added them. Hope you don't mind @lukas-w :)

[tresf]

@lukas-w the error from Circle-CI is:

>>>>> linuxdeployqt
linuxdeployqt 5 (commit fc64c50), build 609 built on 2019-01-06 03:55:18 UTC
Please run on a system no newer than the oldest still-supported Ubuntu LTS release.
This is so that the resulting bundle can run on all still-supported releases of Ubuntu.
Exited with code 1

... this seems to be caused by probonopd/linuxdeployqt@fc64c50

[tresf]

I've tested the built-in presets for SID and they sound indistinguishable when compared to the same presets prior to this patch, merging.

[PhysSong]

... this seems to be caused by probonopd/linuxdeployqt@fc64c50

More precisely, probonopd/linuxdeployqt@b9b57e2 is the right commit. It seems like there were some issues with AppImages created with some build environments. However, I think they should have made linuxdeployqt print a warning when building on a newer environment.