[SYCL] Use MapVector instead of DenseMap to get deterministtic order of attr

llvm/llvm-project#96282 changed the hashing,
we may get non-detrministic iteration order if using DenseMap.

This is causing tests to beome flaky.

Fixing it similar to 6644975

Author: jsji

clang/lib/CodeGen/CodeGenModule.h

@@ -627,7 +627,7 @@ class CodeGenModule : public CodeGenTypeCache {
   MetadataTypeMap VirtualMetadataIdMap;
   MetadataTypeMap GeneralizedMetadataIdMap;
 
-  llvm::DenseMap<StringRef, const RecordDecl *> TypesWithAspects;
+  llvm::MapVector<StringRef, const RecordDecl *> TypesWithAspects;
   const EnumDecl *AspectsEnumDecl = nullptr;
   // Helps squashing blocks of TopLevelStmtDecl into a single llvm::Function
   // when used with -fincremental-extensions.