Test for pointer_width in doc tests

Author: h33p

src/structures/paging/mapper/mod.rs

@@ -127,10 +127,12 @@ pub trait Mapper<S: PageSize> {
     /// Create a USER_ACCESSIBLE mapping:
     ///
     /// ```
+    /// # #[cfg(pointer_width = "64")]
     /// # use x86_64::structures::paging::{
     /// #    Mapper, Page, PhysFrame, FrameAllocator,
     /// #    Size4KiB, OffsetPageTable, page_table::PageTableFlags
     /// # };
+    /// # #[cfg(pointer_width = "64")]
     /// # unsafe fn test(mapper: &mut OffsetPageTable, frame_allocator: &mut impl FrameAllocator<Size4KiB>,
     /// #         page: Page<Size4KiB>, frame: PhysFrame) {
     ///         mapper
@@ -212,10 +214,12 @@ pub trait Mapper<S: PageSize> {
     /// the top hierarchy only with USER_ACCESSIBLE:
     ///
     /// ```
+    /// # #[cfg(pointer_width = "64")]
     /// # use x86_64::structures::paging::{
     /// #    Mapper, PhysFrame, Page, FrameAllocator,
     /// #    Size4KiB, OffsetPageTable, page_table::PageTableFlags
     /// # };
+    /// # #[cfg(pointer_width = "64")]
     /// # unsafe fn test(mapper: &mut OffsetPageTable, frame_allocator: &mut impl FrameAllocator<Size4KiB>,
     /// #         page: Page<Size4KiB>, frame: PhysFrame) {
     ///         mapper