Currently we sprinkle NONFAILING all over pseudo-syscall code,
around all individual accesses to fuzzer-generated pointers.
This is tedious manual work and subject to errors.
Wrap execute_syscall invocation with NONFAILING in execute_call once instead.
Then we can remove NONFAILING from all pseudo-syscalls and never get back to this.
Potential downsides: (1) this is coarser-grained and we will skip whole syscall
on invalid pointer, but this is how normal syscalls work as well,
so should not be a problem; (2) we will skip any clean up (closing of files, etc)
as well; but this may be fine as well (programs can perfectly leave open file
descriptors as well).
Update #1918
b458f2c1a6