This is a reland of 1016bbadde
The broken benchmarks causing the revert were not due to this CL.
TEST=vm/cc/TTS
Original change's description:
> [vm/compiler] Add more checks in TTSes for uninstantiated types.
>
> In certain cases, optimized type testing stubs for uninstantiated types
> compare the instantiation of the type arguments for the type against the
> corresponding instance type arguments. Previously, only an identity
> check was generated, so the instantiation had to match the instance type
> argument exactly.
>
> This CL adds checks for the following cases:
> * The instantiated type argument is dynamic, void, or Object.
> * The instance type argument is Null or Never.
>
> When strong null safety is enabled, we also check that the the instance
> type argument is legacy or non-nullable when the instantiated type
> argument is non-nullable Object or that the instantiated type argument
> is nullable or legacy when the instance type argument is Null.
>
> This CL also adds handling for the case where the instantiated or
> instance type argument is not a Type, which is necessary for safely
> retrieving the type class id and nullability, and allocates some
> additional registers in TTSInternalRegs for storing type arguments. On
> ARM7, this requires pushes/pops around type argument checking, because
> we've run out of registers there.
>
> Fixes https://github.com/dart-lang/sdk/issues/40736
>
> TEST=vm/cc/TTS
>
> Bug: https://github.com/dart-lang/sdk/issues/46920
> Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-nnbd-linux-release-x64-try,vm-kernel-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try
> Change-Id: Ib8498fd2b9593b4abb92111f062ed2fc95a45c16
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210681
> Commit-Queue: Tess Strickland <sstrickl@google.com>
> Reviewed-by: Alexander Markov <alexmarkov@google.com>
Bug: https://github.com/dart-lang/sdk/issues/46920
Change-Id: Id84730b3bb292ea7fdfe9ebd8b1fc6e71c64cf22
Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-release-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-nnbd-linux-release-x64-try,vm-kernel-nnbd-linux-release-x64-try,vm-kernel-linux-product-x64-try,vm-kernel-precomp-linux-product-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211901
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
bb1640eec2