ART: Allow to compile interpret-only mips64 files

Include enough infrastructure to allow cross-compiling for mips64,
interpret-only. This includes the instruction-set-features, frame
size info and utils assembler.

Also add a disassembler for oatdump, and support in patchoat.

Note: the runtime cannot run mips64, yet.

Change-Id: Id106581fa76b478984741c62a8a03be0f370d992
diff --git a/patchoat/patchoat.cc b/patchoat/patchoat.cc
index 28f9668..6c86c7b 100644
--- a/patchoat/patchoat.cc
+++ b/patchoat/patchoat.cc
@@ -62,6 +62,8 @@
       if (((e_flags & EF_MIPS_ARCH) == EF_MIPS_ARCH_32R2) ||
           ((e_flags & EF_MIPS_ARCH) == EF_MIPS_ARCH_32R6)) {
         return kMips;
+      } else if ((e_flags & EF_MIPS_ARCH) == EF_MIPS_ARCH_64R6) {
+        return kMips64;
       } else {
         return kNone;
       }