[vm,dyn_modules] Fix Rectangle/MutableRectangle on vm-dyn-aot.

Also allows the --print-classes flag to be used in the AOT runtime if
dynamic modules are enabled and crashes with an appropriate error
message if class finalization fails when loading a member from bytecode.

TEST=co19/LibTest/math/Rectangle co19/LibTest/math/MutableRectangle

Cq-Include-Trybots: luci.dart.try:vm-dyn-linux-debug-x64-try,vm-aot-dyn-linux-debug-x64-try,vm-aot-dyn-linux-product-x64-try
Change-Id: I1921aa0189eb587cd4658c592a779be190af092e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/495724
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>

utils/dynamic_module_runner/dynamic_interface.yaml

@@ -46,6 +46,10 @@ callable:
   - library: 'dart:io'
   - library: 'dart:isolate'
   - library: 'dart:math'
+  # Explicitly add public members of _RectangleBase because they are inherited
+  # by Rectangle/MutableRectangle.
+  - library: 'dart:math'
+    class: '_RectangleBase'
   - library: 'dart:nativewrappers'
   - library: 'dart:typed_data'
   - library: 'dart:vmservice_io'