ART: Rename ArtMethod JNI field

The field is multi-purpose, rename it to data and clean up
accessors in preparation of more checks.

Test: m test-art-host
Change-Id: Ib4b84b7b1a51ca201544bc488ce8770aa858c7fd
diff --git a/imgdiag/imgdiag.cc b/imgdiag/imgdiag.cc
index 214222d..f5669d7 100644
--- a/imgdiag/imgdiag.cc
+++ b/imgdiag/imgdiag.cc
@@ -729,7 +729,7 @@
           os << "        " << reinterpret_cast<void*>(obj) << " ";
           os << "  entryPointFromJni: "
              << reinterpret_cast<const void*>(
-                    art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", ";
+                    art_method->GetDataPtrSize(pointer_size)) << ", ";
           os << "  entryPointFromQuickCompiledCode: "
              << reinterpret_cast<const void*>(
                     art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size))
@@ -810,7 +810,7 @@
           os << "        " << reinterpret_cast<void*>(obj) << " ";
           os << "  entryPointFromJni: "
              << reinterpret_cast<const void*>(
-                    art_method->GetEntryPointFromJniPtrSize(pointer_size)) << ", ";
+                    art_method->GetDataPtrSize(pointer_size)) << ", ";
           os << "  entryPointFromQuickCompiledCode: "
              << reinterpret_cast<const void*>(
                     art_method->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size))