perlapi: Combine all forms of Sv[INU] into one entry each

This makes perlapi more compact, and at the same time, easier for
readers to compare them and decide which form is best suited for their
purposes.

Author: khwilliamson

sv.h

@@ -886,21 +886,6 @@ Unsets the RV status of an SV.
 =for apidoc Am|SV*|SvRV|SV* sv
 Dereferences an RV to return the SV.
 
-=for apidoc Am|IV|SvIVX|SV* sv
-Returns the raw value in the SV's IV slot, without checks or conversions.
-Only use when you are sure C<SvIOK> is true.  See also C<L</SvIV>>.
-
-=for apidoc Am|UV|SvUVX|SV* sv
-Returns the raw value in the SV's UV slot, without checks or conversions.
-Only use when you are sure C<SvUOK> is true.  See also C<L</SvUV>>.
-
-=for apidoc AmD|UV|SvUVXx|SV* sv
-This is an unnecessary synonym for L</SvUVX>
-
-=for apidoc Am|NV|SvNVX|SV* sv
-Returns the raw value in the SV's NV slot, without checks or conversions.
-Only use when you are sure C<SvNOK> is true.  See also C<L</SvNV>>.
-
 =for apidoc Am   |char*      |SvPVX|SV* sv
 =for apidoc_item |const char*|SvPVX_const|SV* sv
 =for apidoc_item |char*      |SvPVX_mutable|SV* sv

sv_inline.h

@@ -773,45 +773,65 @@ Perl_SvPADSTALE_off(SV *sv)
 =for apidoc         SvIV
 =for apidoc_item    SvIV_nomg
 =for apidoc_item m||SvIVx
+=for apidoc_item m||SvIVX
+=for apidoc_item m||SvIVXx
 
-These each coerce the given SV to IV and return it.  The returned value in many
-circumstances will get stored in C<sv>'s IV slot, but not in all cases.  (Use
-C<L</sv_setiv>> to make sure it does).
+These each return the IV contained in the given SV.
 
-As of 5.37.1, all are guaranteed to evaluate C<sv> only once.
+C<SvIVX> returns the raw value in the SV's IV slot, without checks or
+conversions.  Only use when you are sure C<SvIOK> is true.
+C<SvIVXx> is a synonym for C<SvIVX>.
 
-C<SvIVx> is now identical to C<SvIV>, but prior to 5.37.1, it was the only form
-guaranteed to evaluate C<sv> only once.
+In the other forms, conversions may be performed to yield a IV.  The returned
+value in many circumstances will get stored in C<sv>'s IV slot, but not in all
+cases.  (Use C<L</sv_setiv>> to make sure it does).
+All forms except C<SvIVX> now behave identically, except C<SvIV_nomg> does not
+perform 'get_magic'.
 
-C<SvIV_nomg> is the same as C<SvIV>, but does not perform 'get' magic.
+As of 5.37.1, all are guaranteed to evaluate C<sv> only once.  (Prior to
+5.37.1, C<SvIVx> was the only form guaranteed to evaluate C<sv> only once.)
 
 =for apidoc         SvNV
 =for apidoc_item    SvNV_nomg
-=for apidoc_item m||SvNVx
+=for apidoc_item m ||SvNVx
+=for apidoc_item m ||SvNVX
+=for apidoc_item m||SvNVXx
 
-These each coerce the given SV to NV and return it.  The returned value in many
-circumstances will get stored in C<sv>'s NV slot, but not in all cases.  (Use
-C<L</sv_setnv>> to make sure it does).
+These each return the NV contained in the given SV.
 
-As of 5.37.1, all are guaranteed to evaluate C<sv> only once.
+C<SvNVX> returns the raw value in the SV's NV slot, without checks or
+conversions.  Only use when you are sure C<SvNOK> is true.
+C<SvNVXx> is a synonym for C<SvNVX>.
 
-C<SvNVx> is now identical to C<SvNV>, but prior to 5.37.1, it was the only form
-guaranteed to evaluate C<sv> only once.
+In the other forms, conversions may be performed to yield a NV.  The returned
+value in many circumstances will get stored in C<sv>'s NV slot, but not in all
+cases.  (Use C<L</sv_setnv>> to make sure it does).
+All forms except C<SvNVX> now behave identically, except C<SvNV_nomg> does not
+perform 'get_magic'.
 
-C<SvNV_nomg> is the same as C<SvNV>, but does not perform 'get' magic.
+As of 5.37.1, all are guaranteed to evaluate C<sv> only once.  (Prior to
+5.37.1, C<SvNVx> was the only form guaranteed to evaluate C<sv> only once.)
 
-=for apidoc         SvUV
-=for apidoc_item    SvUV_nomg
-=for apidoc_item m||SvUVx
+=for apidoc          SvUV
+=for apidoc_item     SvUV_nomg
+=for apidoc_item  m||SvUVx
+=for apidoc_item  m||SvUVX
+=for apidoc_item  m||SvUVXx
 
-These each coerce the given SV to UV and return it.  The returned value in many
-circumstances will get stored in C<sv>'s UV slot, but not in all cases.  (Use
-C<L</sv_setuv>> to make sure it does).
+These each return the UV contained in the given SV.
 
-As of 5.37.1, all are guaranteed to evaluate C<sv> only once.
+C<SvUVX> returns the raw value in the SV's UV slot, without checks or
+conversions.  Only use when you are sure C<SvUOK> is true.
+C<SvUVXx> is a synonym for C<SvUVX>.
 
-C<SvUVx> is now identical to C<SvUV>, but prior to 5.37.1, it was the only form
-guaranteed to evaluate C<sv> only once.
+In the other forms, conversions may be performed to yield a UV.  The returned
+value in many circumstances will get stored in C<sv>'s UV slot, but not in all
+cases.  (Use C<L</sv_setuv>> to make sure it does).
+All forms except C<SvUVX> now behave identically, except C<SvUV_nomg> does not
+perform 'get_magic'.
+
+As of 5.37.1, all are guaranteed to evaluate C<sv> only once.  (Prior to
+5.37.1, C<SvUVx> was the only form guaranteed to evaluate C<sv> only once.)
 
 =cut
 */