Merge pull request #2546 from cgwalters/drop-aggregate-return

build-sys: Drop `-Werror=aggregate-return`

configure.ac

@@ -49,7 +49,7 @@ CC_CHECK_FLAGS_APPEND([WARN_CFLAGS], [CFLAGS], [\
   -Werror=undef \
   -Werror=incompatible-pointer-types \
   -Werror=misleading-indentation \
-  -Werror=missing-include-dirs -Werror=aggregate-return \
+  -Werror=missing-include-dirs  \
   -Wstrict-aliasing=2 \
   -Werror=unused-result \
 ])])