Fixes for broken Debian build - g++ 4.7 support.

These fix the broken debian lldb build, which is using g++ 4.7.2.

TypeFormat changes:
1. stopped using the C++11 "dtor = default;" construct.
The generated default destructor in the two derived classes wanted
them to have a different throws() semantic that was causing 4.7 to
fail to generate it.  I switched these to empty destructors defined
in the .cpp file.

2. Switched the m_types map from an ordered map to an unordered_map.
g++ 4.7's c++ library supports the C++11 emplace() used by TypeFormat
but the same c++ library's map impl does not.  Since TypeFormat didn't
look like it depended on ordering in the map, I just switched it to
a std::unordered_map.

NativeProcessLinux - g++ 4.7 chokes on lexing the "<::" in
static_cast<::pid_t>(wpid).  g++ 4.8+ and clang are fine with it.
I just put a space in between the "<" and the "::" and that cleared
it up.
Remove move assignment operator to appease older GCCs.