GXemul Code2

Some better bailout in case breakpoints cannot be allocated.

Use sizeof as arg to strlcpy.

Unimplemented MIPS regimm instructions now cause a Reserved Instruction exception.

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TODO updates.

OpenBSD 6.8 -> 6.9.

Do not store word to memory until the CPU has been initialized completely.

Use pseudorandom function, rather than random() to avoid a linker warning on OpenBSD.

Individual CPUs may have different invalidation functions.

Also try compiling with -std=c99 if compiling without first fails.