Add a transformation (and associated fuzzer pass) that takes:

• An existing pointer in the module
• A fresh id for a temporary result

and:

• Backs up the current value that the pointer refers to by loading from the pointer into the temporary result
• Stores an irrelevant zero to the pointer (so that another fuzzer pass can make this more interesting)
• Restores the pointer's original value from the temporary result.

E.g., if p is the existing pointer we might do:

%temporary_result = OpLoad p
OpStore %p %irrelevant_zero
OpStore %p %temporary_result

Other fuzzer passes should be encouraged to replace the irrelevant zero with something interesting, and wrap the restoring OpStore in some control flow to make it less clear that it will be executed.