build: os2: enable X86ASM

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

configure.ac

@@ -318,6 +318,8 @@ case "${host_os}" in
     AC_LIBOBJ([freeaddrinfo])
     AC_LIBOBJ([gai_strerror])
     AC_CHECK_FUNCS([if_nametoindex])
+    X86ASMFLAGS="-f aout"
+    X86ASMDEFS="-DARCH_X86_32=1 -DARCH_X86_64=0 -DPREFIX"
     ;;
   *nacl*)
     SYS=nacl

extras/include/x86/x86inc.asm

@@ -84,6 +84,8 @@
         SECTION .rdata align=%1
     %elif WIN64
         SECTION .rdata align=%1
+    %elifidn __OUTPUT_FORMAT__,aout
+        SECTION .text
     %else
         SECTION .rodata align=%1
     %endif