VHDL Loop Statement error: loop must terminate within 10,000 iterations
I do not know for sure why you get that error message. I would agree with user1155120's comment, this is a tool limitation and not a VHDL's error.

However, they are many incoherent things in your design. So many that I feel you should put your time in revisiting your design instead of fixing it. A list of what I saw:


storage describe a memory of 16GB, yet your entity is called INST_CACHE. Caches usually ranges from few kilobytes to few megabytes. Why 16GB then?
It takes at least 4 bits to simulate a std_logic (since it has 9 possible states). Your design would eat up 64GB of your computer's memory, which is humongous.
You defined storage_array's range as natural range 0 to 2**32 - 1. The problem is, this is impossible in VHDl since natural is a subtype of integer, which can only take values from -2**31 to 2**31-1, hence a natural can't have a range up to 2**32-1.
As user1155120 pointed out, your code inside rising_edge(clk) will likely never execute. To execute, it would requires the signal INIT to change value on the same simulation delta cycle than clk rising. You will also re-trigger the initialization code every time INIT changes, whereas you probably want that code to execute only once.