[clang] [UBSAN] add null, alignment and array-bounds checks (PR #190739)

[VASU SHARMA via cfe-commits]

vasu-the-sharma wrote:

> > **UBSan call count (for test_lhs + test_rhs + test_both):**
> > ```
> > * Without change: 3 (RHS checks only)
> > 
> > * With change: 5 (LHS + RHS checks)
> > ```
> 
> I'm not seeing any `test_rhs` and `test_both`. Based on previous review comments, we would like to avoid `test_both` as having a bad cost/benefit ratio.

Done. I have added `test_rhs_ptr` and `test_rhs_array` and removed `test_both`.


https://github.com/llvm/llvm-project/pull/190739