[CIR] Add syncscope support for atomic load operations

[jiang1997]

Fix #1868

[bcardosolopes]

Thanks for working on this. Almost good, some issues need addressing!

[bcardosolopes]

LGTM

[bcardosolopes]

Few minor nits remaining

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions cpp,c,h -- clang/test/CIR/CodeGen/scoped-atomic-load-store.c clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h clang/include/clang/CIR/MissingFeatures.h clang/lib/CIR/CodeGen/CIRGenAtomic.cpp clang/lib/CIR/CodeGen/CIRGenBuilder.h clang/lib/CIR/CodeGen/CIRGenBuiltin.cpp clang/lib/CIR/CodeGen/CIRGenBuiltinAArch64.cpp clang/lib/CIR/Dialect/IR/CIRDialect.cpp clang/lib/CIR/Dialect/Transforms/TargetLowering/ItaniumCXXABI.cpp clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp clang/lib/CIR/Lowering/ThroughMLIR/LowerCIRLoopToSCF.cpp clang/test/CIR/CodeGen/AArch64/neon-ldst.c

View the diff from clang-format here.

diff --git a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
index 3a101a1fdc..16e1c052ca 100644
--- a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
+++ b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
@@ -1024,9 +1024,7 @@ void cir::LoadOp::setAtomic(cir::MemOrder order, cir::SyncScopeKind scope) {
 
 // TODO(CIR): The final interface here should include an argument for the
 // SyncScope::ID.
-void cir::StoreOp::setAtomic(cir::MemOrder order) {
-  setMemOrder(order);
-}
+void cir::StoreOp::setAtomic(cir::MemOrder order) { setMemOrder(order); }
 
 //===----------------------------------------------------------------------===//
 // VecCreateOp

[bcardosolopes]

Seems like there's also some bad formatting needing fixes