<rdar://problem/14923930>

Constant ValueObjects should clear their description as well as their summary. Rationale being that both can depend on deeper-than-constified data
so both are subject to changes in "unpredictable" ways
To see this consider repeatedly po'ing a persistent variable of a type whose -description result changes at each invocation



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@192259 91177308-0d34-0410-b5e6-96231b3b80d8