[clang] Consistently cache failed constraint normalization (#227086)
Previously, if substituting the parameter mappings of a normalized
constraint failed, Sema::getNormalizedAssociatedConstraints() returned
nullptr, but it stored the partially substituted normal form in
NormalizationCache. So the first lookup for such a declaration failed,
but every later lookup returned the broken normal form, and subsumption
checking and the ambiguous-constraint diagnostics then continued with
it.
I believe this wasn't intentional:
- Before #161671 (e9972debc98c), normalization was a single step, and a
failure was cached as nullptr.
- #161671 added the parameter mapping substitution step. It inserted the
normal form into the cache before substituting, and returned nullptr if
the substitution then failed, leaving the non-null normal form in the
cache.
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[mlir][LLVM] Use a disjoint scope domain when inlining noalias
This matches recent changes to the LLVM inliner.
AI disclosure: Claude wrote the code, I wrote the commit message and
have done initial review.
[mlir][LLVM] Add disjointScopes to AliasScopeDomainAttr
This also updates the MLIR-side inliner to clone disjoint domains
while cloning alias scopes, matching changes to LLVM.
AI disclosure: Claude wrote the code, I wrote the commit message and
looked at the code.
[AMDGPU] Use a disjoint scope domain for merged LDS structs
When lowering LDS values, all the values are mutually disjoint, so we
can use the newly-added disjoint scopes feature to simplify the IR.
AI disclosure: Claude wrote this and I reviewed it and wrote the
commit message
[AMDGPU] Use a disjoint scope domain for noalias kernel arguments
All noalias arguments of a kernel are disjoint with each other, so we
can use a disjoint scope to save on metadata construction.
AI disclosure: Claude wrote this, I looked at it and wrote this
message.
[Inliner] Use a disjoint scope domain for noalias arguments
InlineFunction creates alias.scope/noalias metadata to represent the
set of `noalias` arguments to a function. We don't need the `!noalias`
now that we have the ability to use disjoint scopes, saving us IR size
and metadata bloat.
TODO move these to a previous commit.
Also changes InstCombine to not drop the experimental.noalias.scope.decl
for disjoint scopes even if they're not mentioned in a `!noalias`, but
do still delete them if they're not used.
