Remove outdated comment

valuescript_compiler/src/expression_compiler.rs

@@ -747,11 +747,6 @@ impl<'a> ExpressionCompiler<'a> {
               }
             };
 
-            // Always copy pre-increment value into a register.
-            // This is a bit heavy-handed (FIXME), but it's consistent with the current policy of
-            // doing this whenever the variable is mutated, which it clearly is. Really though, the
-            // issue is when *other* mutations to this variable occur between now and when it's
-            // inserted.
             self
               .fnc
               .push(Instruction::Mov(Value::Register(reg.clone()), res.clone()));