[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>