removed unnecessary masking in Swap() calls

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@28613 3ad0048d-3df7-0310-abae-a5850022a9f2
a slightly better generic implementation for SwapEndian() 32 bit and 64 bit ints

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@28614 3ad0048d-3df7-0310-abae-a5850022a9f2