Debugger: Remove #ifdef Q_OS_WIN from hostutils.

- Provide stubs for Non-Windows
- Reduce #ifdefs, check Abi if possible.
- Remove unused winGetCurrentProcessId().

Task-number: QTCREATORBUG-8141
Change-Id: I80558ca4e52e87c7371597ea07c091af08097b34
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/cdb/cdbparsehelpers.cpp

@@ -413,10 +413,8 @@ QString WinException::toString(bool includeLocation) const
 {
     QString rc;
     QTextStream str(&rc);
-#ifdef Q_OS_WIN
     formatWindowsException(exceptionCode, exceptionAddress,
                            exceptionFlags, info1, info2, str);
-#endif
     if (includeLocation) {
         if (lineNumber) {
             str << " at " << QLatin1String(file) << ':' << lineNumber;