Correction for the fix for Bug 3508 - Persistent storage support breaks Linux compatibility.
A 2nd `make install' will fail attempting to create symlink libnvmemmory.so already created by 1st install.
Install should pre-emptively delete it.
enum {
#define DEFO32(name, offset) QREG_##name,
#define DEFR(name, reg, mode) QREG_##name,
#define DEFF64(name, offset) QREG_##name,
QREG_NULL,
#include "qregs.def"
TARGET_NUM_QREGS = 0x100
#undef DEFO32
#undef DEFR
#undef DEFF64
};