Add Mips abiflags section to the oatfile.

Once this patch is merged, then the workaround patch:
0acb15ead6a554a6879b29fd90726b9ea8fd98c4
in bionic can be removed.

Change-Id: Ie06a3c4e384a23a77db7d04a2508edbf3a6d3933
diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index e35662d..bed864b 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -210,6 +210,9 @@
   if (bss_size_ != 0u) {
     builder_->GetBss()->WriteNoBitsSection(bss_size_);
   }
+  if (builder_->GetIsa() == kMips || builder_->GetIsa() == kMips64) {
+    builder_->WriteMIPSabiflagsSection();
+  }
   builder_->WriteDynamicSection();
 }