autotool: Add -Wc99-extensions CFLAGS

See with CMake (ga9070e1a90)

Change-Id: If768b663f9ed032503fc121785b078c0107cdadc
Reviewed-on: https://code.wireshark.org/review/15909
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>

diff --git a/configure.ac b/configure.ac
index c051caabc474194fd1b1f7664a35df840d500905..930d3ca459363430df78b0021e4abc99f5954dc5 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -686,6 +686,9 @@ then
        fi
 fi
 
+#Clang only
+AC_WIRESHARK_COMPILER_FLAGS_CHECK(-Wc99-extensions, C)
+
 #
 # Try to add some additional checks to CFLAGS.
 # These are not enabled by default, because the warnings they produce