message: build: Drop -Wno-unused-local-typedef
  Wunused-local-typedef(s) is covered by -Wunused in both gcc and clang.
  No new warnings fire when compiling.
diff: @@ -449,7 +449,6 @@ if test "x$CXXFLAGS_overridden" = "xno"; then
  dnl set the -Wno-foo case if it works.
  AX_CHECK_COMPILE_FLAG([-Wunused-parameter],[NOWARN_CXXFLAGS="$NOWARN_CXXFLAGS -Wno-unused-parameter"],,[[$CXXFLAG_WERROR]])
  AX_CHECK_COMPILE_FLAG([-Wself-assign],[NOWARN_CXXFLAGS="$NOWARN_CXXFLAGS -Wno-self-assign"],,[[$CXXFLAG_WERROR]])
  - AX_CHECK_COMPILE_FLAG([-Wunused-local-typedef],[NOWARN_CXXFLAGS="$NOWARN_CXXFLAGS -Wno-unused-local-typedef"],,[[$CXXFLAG_WERROR]])
  if test x$suppress_external_warnings != xyes ; then
  AX_CHECK_COMPILE_FLAG([-Wdeprecated-copy],[NOWARN_CXXFLAGS="$NOWARN_CXXFLAGS -Wno-deprecated-copy"],,[[$CXXFLAG_WERROR]])
  fi
  