This reverts commit 047db150c66e245e9df7db178b893ce6b29820f5.
The original version of the commit caused assertion failures in DSE.
Those were fixed in ec059d81aafedb253a02d6f490ad9b9747611038, so trying
to reland this again.
This helps to clean up any dead stores that come up at the end of the
destructor. The motivating example was a refactoring in libc++'s
basic_string implementation in 8dae17be2991cd7f0d7fd9aa5aecd064520a14f6
that added a zeroing store into the destructor, causing a large
performance regression on an internal workload. We also saw a ~0.2%
performance increase on an internal server workload when enabling this.
I also tested this against all of the non-flaky tests in our large C++
codebase and found a minimal number of issues that all happened to be in
user code.
Generate nuw GEPs for struct member accesses, as inbounds + non-negative
implies nuw.
Regression tests are updated using update scripts where possible, and by
find + replace where not.
This makes codegen for array initialization simpler in two ways:
1. Drop the zero-index GEP at the start, which is no longer needed with
opaque pointers.
2. Emit GEPs directly to the correct element, instead of having a long
chain of +1 GEPs. This is more canonical, and also avoids regressions in
unoptimized builds from #93823.
Fix#69214
In `emitOMPSimdRegion`, the `EmitOMPPrivateLoopCounters` should be after
`EmitOMPPrivateClause`.
If not, the private variables will be registered too early, which is not
allowed by `EmitOMPPrivateClause`.
