Add a couple more cast macros

src/include/86box/86box.h

@@ -87,6 +87,8 @@
 #define AS_I16(x)    (*((int16_t *) &(x)))
 #define AS_I32(x)    (*((int32_t *) &(x)))
 #define AS_I64(x)    (*((int64_t *) &(x)))
+#define AS_FLOAT(x)  (*((float *) &(x)))
+#define AS_DOUBLE(x) (*((double *) &(x)))
 
 #if defined(__GNUC__) || defined(__clang__)
 #    define UNLIKELY(x) __builtin_expect((x), 0)