fix strict aliasing issues

Patch by Przemysław Iskra (#3805)

code/qcommon/q_shared.c

@@ -205,16 +205,11 @@ qint64 Long64NoSwap (qint64 ll)
 	return ll;
 }
 
-typedef union {
-    float	f;
-    unsigned int i;
-} _FloatByteUnion;
-
 float FloatSwap (const float *f) {
-	_FloatByteUnion out;
+	floatint_t out;
 
 	out.f = *f;
-	out.i = LongSwap(out.i);
+	out.ui = LongSwap(out.ui);
 
 	return out.f;
 }