Also fix return type of _storeAbiSpecificInt / _storeAbiSpecificIntAtIndex (they actually return null,
so declaring return type 'int' violates soundness of types).
TEST=ci
Change-Id: Ic7726e618a5d8dda189f81464c213629d70c23a1
Cq-Include-Trybots: luci.dart.try:vm-aot-dyn-linux-debug-x64-try,vm-aot-dyn-linux-product-x64-try,vm-dyn-linux-debug-x64-try,vm-dyn-mac-debug-arm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/447480
Reviewed-by: Tess Strickland <sstrickl@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Alexander Markov
43aa985577