awk: remove custom pool allocator for temporary awk variables

It seems to be designed to reduce overhead of malloc's auxiliary data,
by allocating at least 64 variables as a block.
With "struct var" being about 20-32 bytes long (32/64 bits),
malloc overhead for one temporary indeed is high, ~33% more memory used
than needed.

function                                             old     new   delta
evaluate                                            3137    3145      +8
modprobe_main                                        798     803      +5
exec_builtin                                        1414    1419      +5
awk_printf                                           476     481      +5
as_regex                                             132     137      +5
EMSG_INTERNAL_ERROR                                   15       -     -15
nvfree                                               169     116     -53
nvalloc                                              145       -    -145
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 5/1 up/down: 28/-213)          Total: -185 bytes

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