perlapi: Fix SvIOK_UV, SvUOK descriptions

Commit b630937b8bf49e835d8976fc1036e68c79585b04 changed the text
of these two macros to how they currently work, but we don't
want to be tied to this behavior in the future.

New wording suggested by Darin McBride

diff --git a/sv.h b/sv.h
index 5e14252..54d606b 100644 (file)
--- a/sv.h
+++ b/sv.h
@@ -655,12 +655,14 @@ Tells an SV that it is an integer and disables all other OK bits.
 Tells an SV that it is an unsigned integer and disables all other OK bits.
 
 =for apidoc Am|bool|SvIOK_UV|SV* sv
-Returns a boolean indicating whether the SV contains an unsigned integer
-that is too large to store as an IV.
+Returns a boolean indicating whether the SV contains an integer that must be
+interpreted as unsigned.  A non-negative integer whose value is within the
+range of both an IV and a UV may be be flagged as either SvUOK or SVIOK.
 
 =for apidoc Am|bool|SvUOK|SV* sv
-Returns a boolean indicating whether the SV contains an unsigned integer
-that is too large to store as an IV.
+Returns a boolean indicating whether the SV contains an integer that must be
+interpreted as unsigned.  A non-negative integer whose value is within the
+range of both an IV and a UV may be be flagged as either SvUOK or SVIOK.
 
 =for apidoc Am|bool|SvIOK_notUV|SV* sv
 Returns a boolean indicating whether the SV contains a signed integer.