configure: Enable -Werror=uninitialized

configure

@@ -5388,6 +5388,34 @@ fi
 
 if test "$GCC" = yes -a "$ICC" = no; then
   CFLAGS="$CFLAGS -Wall -Wmissing-prototypes -Wpointer-arith"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if $CC supports -Werror=uninitialized" >&5
+$as_echo_n "checking if $CC supports -Werror=uninitialized... " >&6; }
+pgac_save_CFLAGS=$CFLAGS
+CFLAGS="$pgac_save_CFLAGS -Werror=uninitialized"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  CFLAGS="$pgac_save_CFLAGS"
+                    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+
   # These work in some but not all gcc versions
   # GPDB code is full of declarations after statement.
   #PGAC_PROG_CC_CFLAGS_OPT([-Wdeclaration-after-statement])

configure.in

@@ -596,6 +596,7 @@ fi
 
 if test "$GCC" = yes -a "$ICC" = no; then
   CFLAGS="$CFLAGS -Wall -Wmissing-prototypes -Wpointer-arith"
+  PGAC_PROG_CC_CFLAGS_OPT([-Werror=uninitialized])
   # These work in some but not all gcc versions
   # GPDB code is full of declarations after statement.
   #PGAC_PROG_CC_CFLAGS_OPT([-Wdeclaration-after-statement])