fix strict aliasing issues

Patch by Przemysław Iskra (#3805)

code/qcommon/q_shared.h

@@ -151,6 +151,12 @@ typedef unsigned char 		byte;
 
 typedef enum {qfalse, qtrue}	qboolean;
 
+typedef union {
+	float f;
+	int i;
+	unsigned int ui;
+} floatint_t;
+
 typedef int		qhandle_t;
 typedef int		sfxHandle_t;
 typedef int		fileHandle_t;