[Sema] Try 2: Sanity-check alignment requested via `__attribute__…

Authored by lebedev.ri on Jan 23 2020, 11:48 AM.


[Sema] Try 2: Sanity-check alignment requested via __attribute__((assume_aligned(imm)))

For __builtin_assume_aligned(), we do validate that the alignment
is not greater than 536870912 (D68824), but we don't do that for
__attribute__((assume_aligned(N))) attribute.
I suspect we should.

This was initially committed in a4cfb15d15a8a353fe316f2a9fe1c8c6a6740ef1
but reverted in 210f0882c9e5d6f504b8f29e8a5eae884f812e5c due to
suspicious bot failures.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72994