T x;
U y;
doing
x = *((T*)y)
is undefined behavior, even if sizeof(T) == sizeof(U), due to pointer aliasing rules
Fix up a couple of places in LLDB that were doing this, and transform them into a defined and safe memcpy() operation
Also, add a test case to ensure we didn't regress by doing this w.r.t. tagged pointer NSDate instances
llvm-svn: 270793