mark conditional branches and string loops as predicated

From bruen...@google.com on October 30, 2014 18:52:04

The new predication API (xref issue #269 (closed) , issue #1181 (closed) ) should probably consider general conditional branches to also be predicated. For x86, OP_jcc is simple to translate to DR_PRED_ constants -- but we'd have to add new ones or ensure DR_PRED_COMPLEX's assumptions hold for OP_jecxz.

What about OP_rep_movs for when ecx is 0?

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=1556