mmap-wx: fix GCC pedantic warning by casting pointers to special integer types

mmap-wx-simple.c: In function 'main':
mmap-wx-simple.c:51:16: warning: ISO C forbids conversion of object pointer to function pointer type [-Wpedantic]
     result = ( (int (*)())xptr )();
                ^
windows_example: fix integer-ptr casts and use PRIxPTR instead of %p

"%p" is like "%016llX" in x86_64, which gives lengthy outputs.
Using "%"PRIxPTR instead leads to shorter lines in the output.
windows_examples: only add one EOL after an error message
linux_examples/sched_migrate_cpu: add new program to show how to choose the CPU to be used