ART: Key-Value Store in Oat header

Allows the storage of string-string pairs in the oat header. The
first significant use of this is storing the implicit-check flags,
so that an oat file can be rejected if it doesn't agree with the
current runtime.

Bump the oat version as the header structure changes.

Change-Id: I15a1c16886e6b8fa7b881c918c19c1efa5c7c00f
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 60453c3..0e4028b 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -1163,7 +1163,9 @@
   OatFile& oat_file = GetImageOatFile(space);
   CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatChecksum(), 0U);
   CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatDataBegin(), 0U);
-  CHECK(oat_file.GetOatHeader().GetImageFileLocation().empty());
+  const char* image_file_location = oat_file.GetOatHeader().
+      GetStoreValueByKey(OatHeader::kImageLocationKey);
+  CHECK(image_file_location == nullptr || *image_file_location == 0);
   portable_resolution_trampoline_ = oat_file.GetOatHeader().GetPortableResolutionTrampoline();
   quick_resolution_trampoline_ = oat_file.GetOatHeader().GetQuickResolutionTrampoline();
   portable_imt_conflict_trampoline_ = oat_file.GetOatHeader().GetPortableImtConflictTrampoline();