VM: Load-forwarding of non-final field values at allocations.

Instead of ignoring escaping allocations, we now forward values
for all non-final fields and type arguments even if the object
 escapes. For non-escaping objects we forward all fields.

R=vegorov@google.com

Review URL: https://codereview.chromium.org//701113003

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41522 260f80e4-7a28-3924-810f-c04153c831b5
Landing bug fix in type propagation.

Original CL: https://codereview.chromium.org/684313003/
TBR=koda@google.com

Review URL: https://codereview.chromium.org//708493002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41523 260f80e4-7a28-3924-810f-c04153c831b5