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

[Vitaly Buka via llvm-commits]

https://github.com/vitalybuka requested changes to this pull request.

We need a real SourceLocation().

I applied the patch and see:

`test.so+0xbc38): runtime error store to misaligned address`

but for existing alignment checks I see:
`strings/join_test.cc:221:39: runtime error: load of misaligned`

I guess we need to forward `getExprLoc` from callers.

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