Turn on more compiler warnings

* configure.ac (gl_WARN_ADD): Add -Wempty-body, -Wformat-security,
-Wignored-qualifiers, -Winit-self, -Wlogical-op,
-Wmissing-parameter-type, -Wnested-externs, -Wold-style-declaration,
-Wold-style-definition, -Wtype-limits.

configure.ac

@@ -244,8 +244,18 @@ AC_DEFINE_UNQUOTED([ENABLE_ARM_OABI], [$enable_arm_oabi],
 		   [Define to 1 if you want OABI support on ARM EABI.])
 
 gl_WARN_ADD([-Wall])
-gl_WARN_ADD([-Wwrite-strings])
+gl_WARN_ADD([-Wempty-body])
+gl_WARN_ADD([-Wformat-security])
+gl_WARN_ADD([-Wignored-qualifiers])
+gl_WARN_ADD([-Winit-self])
+gl_WARN_ADD([-Wlogical-op])
+gl_WARN_ADD([-Wmissing-parameter-type])
+gl_WARN_ADD([-Wnested-externs])
+gl_WARN_ADD([-Wold-style-declaration])
+gl_WARN_ADD([-Wold-style-definition])
 gl_WARN_ADD([-Wsign-compare])
+gl_WARN_ADD([-Wtype-limits])
+gl_WARN_ADD([-Wwrite-strings])
 AC_ARG_ENABLE([gcc-Werror],
   [AS_HELP_STRING([--enable-gcc-Werror], [turn on gcc's -Werror option])],
   [case $enableval in