Add null RegisterContext assertions

This makes these failures slightly more obvious, avoiding the need to
run LLDB under a debugger or rely on a LLDB core.  I encountered these
while bringing up a new OS/arch combination.

llvm-svn: 230236

1 files changed, 1 insertions, 0 deletions

diff --git a/lldb/source/Target/StackFrameList.cpp b/lldb/source/Target/StackFrameList.cpp
index 9a132618288..43a4b5b122f 100644
--- a/lldb/source/Target/StackFrameList.cpp
+++ b/lldb/source/Target/StackFrameList.cpp
@@ -343,6 +343,7 @@ StackFrameList::GetFramesUpTo(uint32_t end_idx)
                 m_frames.push_back (unwind_frame_sp);
             }
             
+            assert(unwind_frame_sp);
             SymbolContext unwind_sc = unwind_frame_sp->GetSymbolContext (eSymbolContextBlock | eSymbolContextFunction);
             Block *unwind_block = unwind_sc.block;
             if (unwind_block)