[lldb] Fix compile error. (llvm#130091)

Followup to
llvm@878a64f

(cherry picked from commit 4022d78)

Author: akuegel

lldb/source/Plugins/ABI/ARC/ABISysV_arc.cpp

@@ -459,7 +459,9 @@ ABISysV_arc::GetReturnValueObjectSimple(Thread &thread,
   const uint32_t type_flags = compiler_type.GetTypeInfo();
   // Integer return type.
   if (type_flags & eTypeIsInteger) {
-    const size_t byte_size = compiler_type.GetByteSize(&thread).value_or(0);
+    const size_t byte_size =
+        llvm::expectedToOptional(compiler_type.GetByteSize(&thread))
+            .value_or(0);
     auto raw_value = ReadRawValue(reg_ctx, byte_size);
 
     const bool is_signed = (type_flags & eTypeIsSigned) != 0;
@@ -483,7 +485,9 @@ ABISysV_arc::GetReturnValueObjectSimple(Thread &thread,
 
     if (compiler_type.IsFloatingPointType(float_count, is_complex) &&
         1 == float_count && !is_complex) {
-      const size_t byte_size = compiler_type.GetByteSize(&thread).value_or(0);
+      const size_t byte_size =
+          llvm::expectedToOptional(compiler_type.GetByteSize(&thread))
+              .value_or(0);
       auto raw_value = ReadRawValue(reg_ctx, byte_size);
 
       if (!SetSizedFloat(value.GetScalar(), raw_value, byte_size))