Work around a bug in the C++ expression parser.

When the expression parser does name resolution for local
variables in C++ closures it doesn't give the local name
priority over other global symbols of the same name.  heap.py
uses "info" which is a fairly common name, and so the commands
in it fail.  This is a workaround, just use lldb_info not info.

<rdar://problem/34026140>

llvm-svn: 314959