Change naive_bytecount applicability to MaybeIncorrect
We can't use `MachineApplicable` here as applying the fix will cause
another error because `bytecount` would first have to be added to the
Cargo.toml.
Example:
```
error: You appear to be counting bytes the naive way
--> $DIR/bytecount.rs:5:13
|
LL | let _ = x.iter().filter(|&&a| a == 0).count(); // naive byte count
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider using the bytecount crate: `bytecount::count(x, 0)`
```
Just replacing it with the suggestion is not enough.
cc #3630
Change while_let_loop applicability to HasPlaceholders
The suggestion has been changed at some point to use `..` in the suggested code.
Due to that we can't make the lint MachineApplicable anymore.
cc #3630
This was causing two different ICEs in #3741.
The first was fixed in #3925.
The second one is fixed with this commit: We just don't `expect`
anymore. If the snippet doesn't contain an `else`, we stop emitting the
lint because it's not a suspiciously formatted else anyway.
Fix ICE in decimal_literal_representation lint
Handling the integer parsing properly instead of just unwrapping.
Note that the test is not catching the ICE because plain UI tests
[currently hide ICEs][compiletest_issue]. Once that issue is fixed, this
test would fail properly again.
Fixes#3891
[compiletest_issue]: https://github.com/laumann/compiletest-rs/issues/169
Handling the integer parsing properly instead of just unwrapping.
Note that the test is not catching the ICE because plain UI tests
[currently hide ICEs][compiletest_issue]. Once that issue is fixed, this
test would fail properly again.
[compiletest_issue]: https://github.com/laumann/compiletest-rs/issues/169
Fix `explicit_counter_loop` suggestion
#1670
This code seems to me to work, but I have two question.
* Because range expression desugared in hir, `Sugg::hir` doesn't add parenthesis to range expression. Which function is better to check range do you think, `check_for_loop_explicit_counter` or `hir_from_snippet`?
* Do you think we need to distinguish between range expression and struct expression that creates `std::ops::Range*`?
* Late Lint pass, catches:
* One liner: 0 -> null -> transmute
* One liner: std:null() -> transmute
* Const (which resolves to null) -> transmute
* UI Test case for Lint
* Updated test for issue 3849, because now the lint that code generated is in Clippy.
* Expanded `const.rs` miri-based Constant Folding code, to cover
raw pointers
