Recognize NaCl OS ABI for all ELF files.

gdb/nacl-tdep.c

Index: gdb/nacl-tdep.c
diff --git a/gdb/nacl-tdep.c b/gdb/nacl-tdep.c
index fe485b13b35f67c8461824bf90d8bea93a12dacd..da118e471eed20618ce9abfbd06d1045f91ffc68 100644
--- a/gdb/nacl-tdep.c
+++ b/gdb/nacl-tdep.c
@@ -36,10 +36,18 @@
 static enum gdb_osabi
 nacl_osabi_sniffer (bfd *abfd)
 {
-  /* WARNING! This way of checking for NaCl OS ABI is deprecated.
-     See http://code.google.com/p/nativeclient/issues/detail?id=2971  */
-  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour &&
-      elf_elfheader (abfd)->e_ident[EI_OSABI] == 123)
+  /* We removed Linux remote debugging support from NaCl debugger, so we must
+     handle all ELF files ourselves now.
+
+     If we want to support both Linux and NaCl remote debugging simultaneously,
+     we would have to find some way to distinguish NaCl and Linux binaries here.
+     Currently there is no way to distinguish PNaCl-produced binaries from
+     Linux binaries.
+
+     See issues https://code.google.com/p/nativeclient/issues/detail?id=2971 and
+     https://code.google.com/p/nativeclient/issues/detail?id=3313
+     for details.  */
+  if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
     return GDB_OSABI_NACL;
 
   return GDB_OSABI_UNKNOWN;