*: add FAST_FUNC to function ptrs where it makes sense

*: add FAST_FUNC to function ptrs where it makes sense

function                                             old     new   delta
evalcommand                                         1195    1209     +14
testcmd                                                -      10     +10
printfcmd                                              -      10     +10
echocmd                                                -      10     +10
func_exec                                            270     276      +6
echo_dg                                              104     109      +5
store_nlmsg                                           85      89      +4
pseudo_exec_argv                                     195     198      +3
dotcmd                                               287     290      +3
machtime_stream                                       29      31      +2
discard_stream                                        24      26      +2
argstr                                              1299    1301      +2
killcmd                                              108     109      +1
evalfor                                              226     227      +1
daytime_stream                                        43      44      +1
run_list                                            2544    2543      -1
lookupvar                                             62      61      -1
ipaddr_modify                                       1310    1309      -1
...
parse_stream                                        2254    2245      -9
evalpipe                                             356     347      -9
collect_if                                           210     197     -13
read_opt                                             869     851     -18
handle_dollar                                        681     658     -23
print_addrinfo                                      1342    1303     -39
iterate_on_dir                                       156      59     -97
print_route                                         1709    1609    -100
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 12/130 up/down: 74/-767)       Total: -693 bytes
   text    data     bss     dec     hex filename
 841748     467    7872  850087   cf8a7 busybox_old
 841061     467    7872  849400   cf5f8 busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>