Fixed a problem with materialization and
dematerialization of registers that caused
conditional breakpoint expressions not to
work properly.  Also added a testcase.

<rdar://problem/14129252>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@184451 91177308-0d34-0410-b5e6-96231b3b80d8