rename sub_ptr 😅

Author: bend-n

tests/fail/intrinsics/ptr_offset_from_unsigned_neg.rs

@@ -3,5 +3,5 @@ fn main() {
     let arr = [0u8; 8];
     let ptr1 = arr.as_ptr();
     let ptr2 = ptr1.wrapping_add(4);
-    let _val = unsafe { ptr1.sub_ptr(ptr2) }; //~ERROR: first pointer has smaller address than second
+    let _val = unsafe { ptr1.offset_from_unsigned(ptr2) }; //~ERROR: first pointer has smaller address than second
 }

tests/fail/intrinsics/ptr_offset_from_unsigned_neg.stderr

@@ -1,8 +1,8 @@
 error: Undefined Behavior: `ptr_offset_from_unsigned` called when first pointer has smaller address than second: $ADDR < $ADDR
   --> tests/fail/intrinsics/ptr_offset_from_unsigned_neg.rs:LL:CC
    |
-LL |     let _val = unsafe { ptr1.sub_ptr(ptr2) };
-   |                         ^^^^^^^^^^^^^^^^^^ `ptr_offset_from_unsigned` called when first pointer has smaller address than second: $ADDR < $ADDR
+LL |     let _val = unsafe { ptr1.offset_from_unsigned(ptr2) };
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `ptr_offset_from_unsigned` called when first pointer has smaller address than second: $ADDR < $ADDR
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/pass/ptr_offset.rs

@@ -21,7 +21,7 @@ fn smoke() {
     let _val = ptr.wrapping_sub(0);
     let _val = unsafe { ptr.sub(0) };
     let _val = unsafe { ptr.offset_from(ptr) };
-    let _val = unsafe { ptr.sub_ptr(ptr) };
+    let _val = unsafe { ptr.offset_from_unsigned(ptr) };
 }
 
 fn test_offset_from() {
@@ -32,14 +32,14 @@ fn test_offset_from() {
         let y = x.offset(12);
 
         assert_eq!(y.offset_from(x), 12);
-        assert_eq!(y.sub_ptr(x), 12);
+        assert_eq!(y.offset_from_unsigned(x), 12);
         assert_eq!(x.offset_from(y), -12);
         assert_eq!((y as *const u32).offset_from(x as *const u32), 12 / 4);
         assert_eq!((x as *const u32).offset_from(y as *const u32), -12 / 4);
 
         let x = (((x as usize) * 2) / 2) as *const u8;
         assert_eq!(y.offset_from(x), 12);
-        assert_eq!(y.sub_ptr(x), 12);
+        assert_eq!(y.offset_from_unsigned(x), 12);
         assert_eq!(x.offset_from(y), -12);
     }
 }