Use Explicit Alignment in CmpXchg Functions

Adapt to https://reviews.llvm.org/D97223

Author: CodaFi

lib/IRGen/GenBuiltin.cpp

@@ -647,7 +647,8 @@ if (Builtin.ID == BuiltinValueKind::id) { \
     pointer = IGF.Builder.CreateBitCast(pointer,
                                   llvm::PointerType::getUnqual(cmp->getType()));
     llvm::Value *value = IGF.Builder.CreateAtomicCmpXchg(
-        pointer, cmp, newval, successOrdering, failureOrdering,
+        pointer, cmp, newval, llvm::MaybeAlign(),
+        successOrdering, failureOrdering,
         isSingleThread ? llvm::SyncScope::SingleThread
                        : llvm::SyncScope::System);
     cast<llvm::AtomicCmpXchgInst>(value)->setVolatile(isVolatile);
@@ -715,7 +716,7 @@ if (Builtin.ID == BuiltinValueKind::id) { \
     pointer = IGF.Builder.CreateBitCast(pointer,
                                   llvm::PointerType::getUnqual(val->getType()));
     llvm::Value *value = IGF.Builder.CreateAtomicRMW(
-        SubOpcode, pointer, val, ordering,
+        SubOpcode, pointer, val, llvm::MaybeAlign(), ordering,
         isSingleThread ? llvm::SyncScope::SingleThread
                        : llvm::SyncScope::System);
     cast<AtomicRMWInst>(value)->setVolatile(isVolatile);

lib/IRGen/IRGenFunction.cpp

@@ -668,6 +668,7 @@ void IRGenFunction::emitAwaitAsyncContinuation(
       contAwaitSyncAddr->getType()->getPointerElementType(), 1);
   auto results = Builder.CreateAtomicCmpXchg(
       contAwaitSyncAddr, null, one,
+      llvm::MaybeAlign(),
       llvm::AtomicOrdering::Release /*success ordering*/,
       llvm::AtomicOrdering::Acquire /* failure ordering */,
       llvm::SyncScope::System);
@@ -710,6 +711,7 @@ void IRGenFunction::emitAwaitAsyncContinuation(
 
     auto results = Builder.CreateAtomicCmpXchg(
         contAwaitSyncAddr, null, one,
+        llvm::MaybeAlign(),
         llvm::AtomicOrdering::Release /*success ordering*/,
         llvm::AtomicOrdering::Acquire /* failure ordering */,
         llvm::SyncScope::System);