configure: Enable more compiler warnings

author: Kim Alvefur <zash@zash.se>
date: Sat, 16 Mar 2019 18:51:02 +0100
parent: 9860:2cf3dcf93d74
child: 9999:d2febb4befbc
--- a/configure	Sat Mar 16 18:43:11 2019 +0100
+++ b/configure	Sat Mar 16 18:51:02 2019 +0100
@@ -24,7 +24,7 @@
 PRNGLIBS=
 
 CFLAGS="-fPIC -std=c99"
-CFLAGS="$CFLAGS -Wall -pedantic"
+CFLAGS="$CFLAGS -Wall -pedantic -Wextra -Wshadow -Wformat=2"
 LDFLAGS="-shared"
 
 IDN_LIBRARY="idn"