* InterlockedIncrement/Decrement must return the modified value, not the initial one. Fixes a number of interface memory leaks in MIPS test suite. The functions remain not thread-safe yet.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@23393 3ad0048d-3df7-0310-abae-a5850022a9f2