Fix cast_lossless lint

```
cargo clippy --fix --workspace --exclude bindgen-integration --exclude tests_expectations -- -W clippy::cast_lossless
```

Author: nyurik

bindgen/clang.rs

@@ -1791,7 +1791,7 @@ impl Index {
     pub(crate) fn new(pch: bool, diag: bool) -> Index {
         unsafe {
             Index {
-                x: clang_createIndex(pch as c_int, diag as c_int),
+                x: clang_createIndex(c_int::from(pch), c_int::from(diag)),
             }
         }
     }

bindgen/codegen/mod.rs

@@ -3329,7 +3329,7 @@ impl<'a> EnumBuilder<'a> {
         let is_rust_enum = self.is_rust_enum();
         let expr = match variant.val() {
             EnumVariantValue::Boolean(v) if is_rust_enum => {
-                helpers::ast_ty::uint_expr(v as u64)
+                helpers::ast_ty::uint_expr(u64::from(v))
             }
             EnumVariantValue::Boolean(v) => quote!(#v),
             EnumVariantValue::Signed(v) => helpers::ast_ty::int_expr(v),

bindgen/ir/var.rs

@@ -125,23 +125,24 @@ fn default_macro_constant_type(ctx: &BindgenContext, value: i64) -> IntKind {
         ctx.options().default_macro_constant_type ==
             MacroTypeVariation::Signed
     {
-        if value < i32::MIN as i64 || value > i32::MAX as i64 {
+        if value < i64::from(i32::MIN) || value > i64::from(i32::MAX) {
             IntKind::I64
         } else if !ctx.options().fit_macro_constants ||
-            value < i16::MIN as i64 ||
-            value > i16::MAX as i64
+            value < i64::from(i16::MIN) ||
+            value > i64::from(i16::MAX)
         {
             IntKind::I32
-        } else if value < i8::MIN as i64 || value > i8::MAX as i64 {
+        } else if value < i64::from(i8::MIN) || value > i64::from(i8::MAX) {
             IntKind::I16
         } else {
             IntKind::I8
         }
-    } else if value > u32::MAX as i64 {
+    } else if value > i64::from(u32::MAX) {
         IntKind::U64
-    } else if !ctx.options().fit_macro_constants || value > u16::MAX as i64 {
+    } else if !ctx.options().fit_macro_constants || value > i64::from(u16::MAX)
+    {
         IntKind::U32
-    } else if value > u8::MAX as i64 {
+    } else if value > i64::from(u8::MAX) {
         IntKind::U16
     } else {
         IntKind::U8
@@ -235,7 +236,7 @@ impl ClangSubItemParser for Var {
                                 c as u8
                             }
                             CChar::Raw(c) => {
-                                assert!(c <= u8::MAX as u64);
+                                assert!(c <= u64::from(u8::MAX));
                                 c as u8
                             }
                         };

bindgen/time.rs

@@ -36,7 +36,7 @@ impl<'a> Timer<'a> {
         if self.output {
             let elapsed = self.elapsed();
             let time = (elapsed.as_secs() as f64) * 1e3 +
-                (elapsed.subsec_nanos() as f64) / 1e6;
+                f64::from(elapsed.subsec_nanos()) / 1e6;
             let stderr = io::stderr();
             // Arbitrary output format, subject to change.
             writeln!(stderr.lock(), "  time: {time:>9.3} ms.\t{}", self.name)