Use usize/isize instead of (s)size_t

Since we're using Rust-style integer types already, why not go all in?

kernel/src/MemoryManager.cpp

@@ -157,7 +157,7 @@ namespace MemoryManager
         return {};
     }
 
-    Result<void> remap(u64 address, size_t count, int flags)
+    Result<void> remap(u64 address, usize count, int flags)
     {
         check(is_aligned(address, MMU::page_size()));
 
@@ -170,7 +170,7 @@ namespace MemoryManager
         return {};
     }
 
-    Result<void> remap_unaligned(u64 address, size_t count, int flags)
+    Result<void> remap_unaligned(u64 address, usize count, int flags)
     {
         if (!is_aligned(address, MMU::page_size())) count++;
         address = align_down(address, MMU::page_size());

kernel/src/MemoryManager.h

@@ -14,8 +14,8 @@ namespace MemoryManager
     void lock_page(u64 page);
     void lock_pages(u64 pages, u64 count);
 
-    Result<void> remap(u64 address, size_t count, int flags);
-    Result<void> remap_unaligned(u64 address, size_t count, int flags);
+    Result<void> remap(u64 address, usize count, int flags);
+    Result<void> remap_unaligned(u64 address, usize count, int flags);
 
     u64 free();
     u64 used();

kernel/src/arch/MMU.h

@@ -29,5 +29,5 @@ namespace MMU
     Result<PageDirectory*> create_page_directory_for_userspace();
     void setup_initial_page_directory();
 
-    size_t page_size();
+    usize page_size();
 }

kernel/src/arch/Serial.cpp

@@ -2,7 +2,7 @@
 
 namespace Serial
 {
-    void write(const char* str, size_t size)
+    void write(const char* str, usize size)
     {
         while (size--) putchar(*str++);
     }

kernel/src/arch/Serial.h

@@ -4,7 +4,7 @@
 namespace Serial
 {
     void putchar(u8 c);
-    void write(const char* str, size_t size);
+    void write(const char* str, usize size);
     void print(const char* str);
     void println(const char* str);
 }

kernel/src/arch/x86_64/MMU.cpp

@@ -52,7 +52,7 @@ static_assert(sizeof(PageDirectory) == PAGE_SIZE);
 
 namespace MMU
 {
-    size_t page_size()
+    usize page_size()
     {
         return PAGE_SIZE;
     }

luna/Types.h

@@ -8,4 +8,6 @@ typedef uint64_t u64;
 typedef int8_t i8;
 typedef int16_t i16;
 typedef int32_t i32;
-typedef int64_t i64;
+typedef int64_t i64;
+typedef size_t usize;
+typedef long isize;