[gdb/doc] Stack, Examining the Stack: Reorder menu

[gdb/doc] Stack, Examining the Stack: Reorder menu

Commit fc58fa65d454 (gdb/doc: Restructure frame command documentation)
reordered the sections in the 'Examining the Stack' chapter, but
missed updating the menu:

src/gdb/doc/gdb.texinfo:6968: warning: node next `Backtrace' in menu `Frame Filter Management' and in sectioning `Selection' differ
src/gdb/doc/gdb.texinfo:7167: warning: node prev `Selection' in menu `Frame Filter Management' and in sectioning `Backtrace' differ
src/gdb/doc/gdb.texinfo:7252: warning: node `Frame Filter Management' is next for `Frame Info' in sectioning but not in menu
src/gdb/doc/gdb.texinfo:7317: warning: node `Selection' is next for `Frame Filter Management' in menu but not in sectioning
src/gdb/doc/gdb.texinfo:7317: warning: node prev `Frame Filter Management' in menu `Backtrace' and in sectioning `Frame Info' differ

gdb/doc/ChangeLog:
2015-12-10  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Stack): Reorder menu.