-Wno-implicit

[Bill Allombert <allomber@math.u-bordeaux.fr>]

Hello PARI developers,

./configure make gcc to compile with '-Wall -Wno-implicit'.

Is there a reason to discard -Wimplicit warning ?  They would have saved us a
lot of trouble on ia64. Also they are mandatory for g++.

Here the current list of such warnings :

../src/gp/gp_rl.c: In function `pari_rl_forward_sexp':
../src/gp/gp_rl.c:225: warning: implicit declaration of function `ding'
../src/gp/gp_rl.c: In function `unblock_SIGINT':
../src/gp/gp_rl.c:797: warning: implicit declaration of function `sigrelse'
In file included from ../src/graph/plotgnuplot.c:31:
../src/graph/Gnuplot.h:72: warning: type defaults to `int' in declaration of `outfile_set'
../src/graph/plotgnuplot.c: In function `rectdraw0':
../src/graph/plotgnuplot.c:58: warning: implicit declaration of function `X11_rectdraw0'
../src/graph/plotgnuplot.c: In function `PARI_get_plot':
../src/graph/plotgnuplot.c:235: warning: implicit declaration of function `X11_PARI_get_plot'
../src/graph/plotgnuplot.c: In function `term_set':
../src/graph/plotgnuplot.c:261: warning: implicit declaration of function `X11_term_set'
../src/graph/plotgnuplot.c: In function `set_pointsize':
../src/graph/plotgnuplot.c:372: warning: implicit declaration of function `X11_set_pointsize'

Cheers,
Bill