Unify the invoke stubs and replace "oat" with "Art" in the API.

Change-Id: Ic1529d7568bd5297fdce4da69ede67c2f48487a4
diff --git a/src/compiler_llvm/compiler_llvm.cc b/src/compiler_llvm/compiler_llvm.cc
index 5a3725e..c5e620b 100644
--- a/src/compiler_llvm/compiler_llvm.cc
+++ b/src/compiler_llvm/compiler_llvm.cc
@@ -224,7 +224,7 @@
 
 }  // anonymous namespace
 
-extern "C" art::CompiledMethod* oatCompileMethod(art::Compiler& compiler,
+extern "C" art::CompiledMethod* ArtCompileMethod(art::Compiler& compiler,
                                                  const art::DexFile::CodeItem* code_item,
                                                  uint32_t access_flags, uint32_t method_idx,
                                                  const art::ClassLoader* class_loader,