This patch adds missing includes to the LLDB headers inside include/ as a first step of building LLDB's source with C++ modules. It also fixes this single stds:: typo.
Some quick map why some non-obvious includes were necessary:
- lldb/lldb-defines.h for LLDB_INVALID_ADDRESS
- lldb/lldb-types.h for addr_t
- lldb/lldb-defines.h for DISALLOW_COPY_AND_ASSIG
- lldb/DataFormatters/TypeSynthetic.h for SyntheticChildrenFrontEnd