Option --android-oid for Android < 10

modified:   main.cpp
	modified:   options.h
	modified:   p_lx_elf.cpp
	modified:   p_lx_elf.h
	modified:   p_unix.h

src/options.h

@@ -159,6 +159,7 @@ struct Options final {
         unsigned char osabi0;   // replacement if 0==.e_ident[EI_OSABI]
         bool preserve_build_id; // copy the build-id to the compressed binary
         bool android_shlib;     // keep some ElfXX_Shdr for dlopen()
+        bool android_old;       // < Android_10 ==> no memfd_create, inconsistent __NR_ftruncate
         bool force_pie;         // choose DF_1_PIE instead of is_shlib
     } o_unix;
     struct {