dont handle bool transmute

Author: bend-n

compiler/rustc_mir_transform/src/check_unnecessary_transmutes.rs

@@ -98,8 +98,6 @@ impl<'a, 'tcx> UnnecessaryTransmuteChecker<'a, 'tcx> {
             (Uint(_), Float(ty)) => err(format!("{}::from_bits({arg})", ty.name_str())),
             // bool → { x8 }
             (Bool, Int(..) | Uint(..)) => err(format!("({arg}) as {}", fn_sig.output())),
-            // u8 → bool
-            (Uint(_), Bool) => err(format!("({arg} == 1)")),
             _ => return None,
         })
     }

tests/ui/transmute/unnecessary-transmutation.fixed

@@ -81,13 +81,13 @@ fn main() {
         let y: i64 = f64::to_bits(1f64).cast_signed();
         //~^ ERROR
 
-        let z: bool = (1u8 == 1);
-        //~^ ERROR
+        let z: bool = transmute(1u8);
+        // clippy
         let z: u8 = (z) as u8;
         //~^ ERROR
 
         let z: bool = transmute(1i8);
-        // no error!
+        // clippy
         let z: i8 = (z) as i8;
         //~^ ERROR
     }

tests/ui/transmute/unnecessary-transmutation.rs

@@ -82,12 +82,12 @@ fn main() {
         //~^ ERROR
 
         let z: bool = transmute(1u8);
-        //~^ ERROR
+        // clippy
         let z: u8 = transmute(z);
         //~^ ERROR
 
         let z: bool = transmute(1i8);
-        // no error!
+        // clippy
         let z: i8 = transmute(z);
         //~^ ERROR
     }

tests/ui/transmute/unnecessary-transmutation.stderr

@@ -239,12 +239,6 @@ error: unnecessary transmute
 LL |         let y: i64 = transmute(1f64);
    |                      ^^^^^^^^^^^^^^^ help: replace this with: `f64::to_bits(1f64).cast_signed()`
 
-error: unnecessary transmute
-  --> $DIR/unnecessary-transmutation.rs:84:23
-   |
-LL |         let z: bool = transmute(1u8);
-   |                       ^^^^^^^^^^^^^^ help: replace this with: `(1u8 == 1)`
-
 error: unnecessary transmute
   --> $DIR/unnecessary-transmutation.rs:86:21
    |
@@ -257,5 +251,5 @@ error: unnecessary transmute
 LL |         let z: i8 = transmute(z);
    |                     ^^^^^^^^^^^^ help: replace this with: `(z) as i8`
 
-error: aborting due to 36 previous errors
+error: aborting due to 35 previous errors