Reword

Author: gnzlbg

reference/src/layout/scalars.md

@@ -37,11 +37,11 @@ The `isize` and `usize` types are pointer-sized signed and unsigned integers.
 They have the same layout as the [pointer types] for which the pointee is
 `Sized`, and are layout compatible with C's `uintptr_t` and `intptr_t` types.
 
-> **Note**: on all platforms that we currently support, `usize`/`isize` are at
-> least 16-bit wide. C99
-> [7.18.2.4](https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4) requires
-> `uintptr_t` and `intptr_t` to be at least 16-bit wide. `libcore` relies on
-> this to unconditionally provide impls of `From<i16>`/`From<u16>` for
+> **Note**: C99 [7.18.2.4](https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4)
+> requires `uintptr_t` and `intptr_t` to be at least 16-bit wide. That is, on
+> all platforms that we currently support, which have a C platform,
+> `isize`/`usize` are at least 16-bit wide. `libcore` relies on this guarantee
+> to unconditionally provide impls of `From<i16>`/`From<u16>` for
 > `isize`/`usize`.
 
 > **Note**: Rust's `usize` and C's `unsigned` types are **not** equivalent. C's