Fix vm/cc/StaticNonNullSumCallCodegen.
Fix vm/cc/StaticNonNullSumCallCodegen.

Instead of passing null wrapped in the Smi handle use Instance handle.

We have the following behavior:

Smi::ZoneHandle().IsSmi() -> true
Smi::Cast(Smi::ZoneHandle()).Value() -> assertion failure

This kind of behavior is completely unexpected in most parts of the system.

TBR=iposva@google.com,asiva@google.com

Review URL: https://codereview.chromium.org//473913005

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@39455 260f80e4-7a28-3924-810f-c04153c831b5

dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk