Surrounded table of renamed commands (version within @ifinfo) with

@example/@end example.  Without this it formatted fine by
texinfo-format-buffer in Emacs, but makeinfo insisted on paragraphing
it!

Also removed "gdb/" from in front of one instance of libiberty...

gdb/doc/gdb.texinfo

@@ -5643,8 +5643,9 @@ command set as a whole more consistent and easier to use and remember:
 @kindex unset                      
 
 @ifinfo
+@example
 OLD COMMAND               NEW COMMAND
----------------            ----------------------------------
+---------------           -------------------------------
 add-syms                  add-symbol-file
 delete environment        unset environment
 info convenience          show convenience
@@ -5671,6 +5672,7 @@ set/show unionprint        set/show print union
 set/show vtblprint        set/show print vtbl
 
 unset                     [No longer an alias for delete]
+@end example
 @end ifinfo
 
 @tex
@@ -5837,7 +5839,7 @@ creates the following directories:
 @var{gnusrc}/Host-sun4/Target-vx960
 @var{gnusrc}/bfd/Host-sun4/Target-vx960
 @var{gnusrc}/gdb/Host-sun4/Target-vx960
-@var{gnusrc}/gdb/libiberty/Host-sun4/Target-vx960
+@var{gnusrc}/libiberty/Host-sun4/Target-vx960
 @var{gnusrc}/readline/Host-sun4/Target-vx960
 @end example
 @noindent