Apply perldelta suggestions and comments from Karl Williamson

Co-authored-by: mauke <[email protected]>

Author: thibaultduponchelle

pod/perldelta.pod

@@ -1248,9 +1248,11 @@ lines saved by the debugger. [L<GH #23151|https://github.com/Perl/perl5/issues/2
 
 =item *
 
-Save debugger lines as C<PVIV> SVs rather than as C<PVMG> SVs as they
-don't need magic, aren't blessed and don't need to store a floating
-point part.  This should save 24 bytes per stored line for 64-bit
+In debugging mode, perl saves source lines from all files
+(plus an indication of whether each line is breakable)
+for use by the debugger. The internal storage format has been
+optimized to use less memory.
+This should save 24 bytes per stored line for 64-bit
 systems, more for C<-Duselongdouble> or C<-Dusequadmath> builds.
 Discussed in [L<GH #23171|https://github.com/Perl/perl5/issues/23171>].