Clippy fixes (#2011)

* windows: bump winapi version

* windows: address dark_mode FIXMEs

use now available winapi structures

* clippy: fix clippy::upper_case_acronyms warnings

* clippy: fix needless_arbitrary_self_type warnings

* clippy: fix clone_on_copy warnings

* clippy: fix unnecessary_mut_passed warnings

* clippy: fix identity_op warnings

* clippy: fix misc warnings

* prefix rustdoc lints with rustdoc::

the prefix was introduced in Rust 1.52

* windows: silence file_drop_handler is never read warning

* clippy: fix from_over_into warnings

and a bit of naming simplification

* clippy: fix missing_safety_doc warnings

* make dummy() functions const

src/platform_impl/linux/mod.rs

@@ -141,7 +141,7 @@ pub enum WindowId {
 }
 
 impl WindowId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         #[cfg(feature = "wayland")]
         return WindowId::Wayland(wayland::WindowId::dummy());
         #[cfg(all(not(feature = "wayland"), feature = "x11"))]
@@ -158,7 +158,7 @@ pub enum DeviceId {
 }
 
 impl DeviceId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         #[cfg(feature = "wayland")]
         return DeviceId::Wayland(wayland::DeviceId::dummy());
         #[cfg(all(not(feature = "wayland"), feature = "x11"))]

src/platform_impl/linux/wayland/mod.rs

@@ -22,7 +22,7 @@ mod window;
 pub struct DeviceId;
 
 impl DeviceId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         DeviceId
     }
 }
@@ -31,7 +31,7 @@ impl DeviceId {
 pub struct WindowId(usize);
 
 impl WindowId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         WindowId(0)
     }
 }

src/platform_impl/linux/x11/mod.rs

@@ -490,7 +490,7 @@ impl<'a> Deref for DeviceInfo<'a> {
 pub struct WindowId(ffi::Window);
 
 impl WindowId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         WindowId(0)
     }
 }
@@ -499,7 +499,7 @@ impl WindowId {
 pub struct DeviceId(c_int);
 
 impl DeviceId {
-    pub unsafe fn dummy() -> Self {
+    pub const unsafe fn dummy() -> Self {
         DeviceId(0)
     }
 }