[PATCHv2] Fix minimal alignment calculation for user-aligned types (PR63802)

[Joseph Myers]

On Mon, 17 Nov 2014, Yury Gribov wrote:

> It looks like min_align_of_type is just too C11-specific to be usable in other
> contexts.  Here is a patch which does what Jakub originally proposed (use
> TYPE_ALIGN_UNIT for user-aligned types, fallback to min_align_of_type
> otherwise).

I think the requirements for min_align_of_type and ubsan are exactly the 
same, and we should not create a duplicate function for this.

-- 
Joseph S. Myers
joseph@codesourcery.com