Revise c-variadics changes editorially

Author: traviscross

src/items/external-blocks.md

@@ -190,16 +190,15 @@ unsafe extern "C" {
 > The `safe` qualifier should not be used on a function in an `extern` block unless that function guarantees that it will not access the variadic arguments at all. Passing an unexpected number of arguments or arguments of unexpected type to a variadic function may lead to [undefined behavior][undefined].
 
 r[items.extern.variadic.conventions]
-Variadic parameters can only be specified with `extern` blocks with the following ABI strings:
+Variadic parameters can only be specified within `extern` blocks with the following ABI strings or their corresponding [`-unwind` variants][items.fn.extern.unwind]:
+
 - `"aapcs"`
 - `"C"`
 - `"cdecl"`
 - `"efiapi"`
 - `"sysv64"`
 - `"win64"`
 
-This also includes the corresponding [`-unwind` variants][items.fn.extern.unwind].
-
 r[items.extern.attributes]
 ## Attributes on extern blocks
 

src/types/function-pointer.md

@@ -50,7 +50,7 @@ The `unsafe` qualifier indicates that the type's value is an [unsafe
 function], and the `extern` qualifier indicates it is an [extern function].
 
 r[type.fn-pointer.constraint-variadic]
-For the function to be variadic, its `extern` ABI must be on the [list of ABIs that allow variadic calls][items.extern.variadic.conventions].
+For the function to be variadic, its `extern` ABI must be one of those listed in [items.extern.variadic.conventions].
 
 r[type.fn-pointer.attributes]
 ## Attributes on function pointer parameters