DirectX codegen tests failing when ran under hwasan

[Icohedron]

After the merging of a PR (#128556) fix to DirectX build breaks, 28 DirectX tests are failing when ran under my hwasan build of this PR's branch.
See this log: https://gist.github.com/Icohedron/54739cbd0ab952d666bf376e76c9bb85

Similar to issue #124045, it appears to be related to the use of -o /dev/null with llc

/workspace/llvm-project/build/bin/llc /workspace/llvm-project/llvm/test/CodeGen/DirectX/BufferStore-errors.ll -o /dev/null 2>&1
error: <unknown>:0:0: in function storetoomany void (<5 x float>, i32): typedBufferStore data must be a vector of 4 elements

error: <unknown>:0:0: in function storetoofew void (<3 x i32>, i32): typedBufferStore data must be a vector of 4 elements

pure virtual method called
terminate called without an active exception
Aborted

Replacing -o /dev/null with -o - makes the tests pass.

This is odd because @vitalybuka supposedly patched a similar issue w.r.t. a SPIRV codegen error test ( #125599 (comment) )

[vitalybuka]

pure virtual method called?

I fixed only memory leaks, which where cause of the previous revert

[vitalybuka]

And our HWASAN bot does not fail after #128556 https://lab.llvm.org/buildbot/#/builders/55/builds/7503

[Icohedron]

That's odd. I'll close this issue then. My local hwasan setup may just be outdated.