versioner: handle _FILE_OFFSET_BITS=64.

Compile headers with both -D_FILE_OFFSET_BITS=32 and -D_FILE_OFFSET_BITS=64.

Bug: http://b/30170081
Change-Id: I92651e075cc69bdc1a2581f99892c9a7fdcdb35b
Test: python run_tests.py
diff --git a/tools/versioner/src/DeclarationDatabase.h b/tools/versioner/src/DeclarationDatabase.h
index 8fe12ea..b130ca9 100644
--- a/tools/versioner/src/DeclarationDatabase.h
+++ b/tools/versioner/src/DeclarationDatabase.h
@@ -43,10 +43,11 @@
 struct CompilationType {
   Arch arch;
   int api_level;
+  int file_offset_bits;
 
  private:
   auto tie() const {
-    return std::tie(arch, api_level);
+    return std::tie(arch, api_level, file_offset_bits);
   }
 
  public: