[clang] [compiler-rt] [UBSAN] add null and alignment checks for aggregates (PR #164548)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

> > We need a real SourceLocation().
> 
> The approach from [vasu-the-sharma#1](https://github.com/vasu-the-sharma/llvm-project/pull/1) will get us real source locations (but does not cover all cases where `EmitAggregateCopy` is called).

For UBSAN we need to keep the location. It's supposed to be usable without debug info. Without location it's hard to act on such reports. 

However, how hard to pass it into EmitAggregateCopy?
Maybe we can fork EmitAggregateCopy -> EmitAggregateCopyCurrentOne + EmitAggregateCopyWithSourceLocation 
and incrementally transition from first to another?



https://github.com/llvm/llvm-project/pull/164548