CHERI compiler warnings and errors

The CHERI Clang compiler includes many diagnostic warnings to identify code that is incompatible with CHERI C/C++ or may result in behavioral differences. In many cases, a successful compilation that does not emit any CHERI-specific warnings will result in a functional spatially-safe program. However, some incompatibilities (e.g., memory allocators returning insufficiently aligned pointers) cannot yet be diagnosed statically. This section describes some of the more-commonly seen compiler warnings and provides suggestions on how to change the source code to be compatible with CHERI C/C++. All these warnings are enabled when the -Wall compiler flag is set.