--android-shlib for arm32 and i386

... including work-around if no memfd_create() on early Android 32-bit
	modified:   ../misc/testsuite/upx_testsuite_1-expected_sha256sums.sh
	modified:   p_elf_enum.h
	modified:   p_lx_elf.cpp
	modified:   stub/src/arm.v4a-linux.elf-so_entry.S
	modified:   stub/src/arm.v4a-linux.elf-so_fold.S
	modified:   stub/src/i386-linux.elf-so_main.c
	modified:   stub/src/upxfd_android.c
           plus generated *.h *.dump *.map

src/p_elf_enum.h

@@ -138,6 +138,7 @@ class Dummy {
         SHT_PREINIT_ARRAY = 16,       /* Array of pre-constructors */
         SHT_GROUP = 17,               /* Section group */
         SHT_SYMTAB_SHNDX = 18,        /* Extended section indices */
+        SHT_RELR = 19,                /* RELR relative relocations */
         SHT_GNU_HASH = 0x6ffffff6,    /* GNU-style hash table.  */
         SHT_GNU_LIBLIST = 0x6ffffff7, /* Prelink library list */
         SHT_GNU_verdef = 0x6ffffffd,  /* Version definition section.  */