Fix clippy errors

kernel/src/arch/x86_64/interrupts.rs

@@ -40,7 +40,7 @@ pub enum InterruptIndex {
 }
 
 impl InterruptIndex {
-    fn as_u8(self) -> u8 {
+    const fn as_u8(self) -> u8 {
         self as u8
     }
 

kernel/src/arch/x86_64/memmap.rs

@@ -48,9 +48,8 @@ pub static _KERNEL_PHYSICAL_MEMORY_OFFSET: Lazy<(u64, u64)> = Lazy::new(|| {
 ///
 /// Panics if the memory map was not found in MEMORY_MAP_REQUEST.
 pub fn get_memory_map() -> &'static MemoryMapResponse {
-    if let Some(memory_map) = MEMORY_MAP_REQUEST.get_response() {
-        memory_map
-    } else {
-        unreachable!("Could not fetch memory map from Limine.")
-    }
+    MEMORY_MAP_REQUEST.get_response().map_or_else(
+        || unreachable!("Could not fetch memory map from Limine."),
+        |memory_map| memory_map,
+    )
 }

kernel/src/arch/x86_64/memory.rs

@@ -55,7 +55,7 @@ pub unsafe fn init(physical_memory_offset: VirtAddr) -> OffsetPageTable<'static>
     }
 }
 
-pub(crate) struct FoundryOSFrameAllocator {
+pub struct FoundryOSFrameAllocator {
     memory_map: &'static MemoryMapResponse,
     next: usize,
 }
@@ -66,8 +66,8 @@ impl FoundryOSFrameAllocator {
     /// This function takes a reference to a `MemoryMapResponse` and initializes a
     /// `FoundryOSFrameAllocator` with it. The `next` field is set to 0, indicating that
     /// the first frame to be allocated is the first frame in the memory map.
-    pub unsafe fn init(memory_map: &'static MemoryMapResponse) -> FoundryOSFrameAllocator {
-        FoundryOSFrameAllocator {
+    pub const unsafe fn init(memory_map: &'static MemoryMapResponse) -> Self {
+        Self {
             memory_map,
             next: 0,
         }

kernel/src/arch/x86_64/mod.rs

@@ -4,4 +4,4 @@ pub mod interrupts;
 
 pub mod memory;
 
-pub(crate) mod memmap;
+pub mod memmap;