Cleanup #22182 (#22205)

* Turns compute_units_consumed of ProcessInstructionResult into a &mut parameter.

* Removes second nesting level from test_process_instruction_compute_budget().

* Makes test_process_cross_program and test_native_invoke symmetric.

* Unifies test_process_cross_program(), test_native_invoke() and test_process_instruction_compute_budget() into test_process_instruction().

programs/bpf_loader/src/syscalls.rs

@@ -2384,14 +2384,15 @@ fn call<'a, 'b: 'a>(
     )?;
 
     // Process instruction
+    let mut compute_units_consumed = 0;
     invoke_context
         .process_instruction(
             &instruction.data,
             &instruction_accounts,
             Some(&caller_write_privileges),
             &program_indices,
+            &mut compute_units_consumed,
         )
-        .result
         .map_err(SyscallError::InstructionError)?;
 
     // Copy results back to caller