Use ELF function index to distinguish generated functions.

We replaced LLVMLongName and LLVMStubName with ElfFuncName,
and we are using the simple name: Art0, Art1, ..., ArtN,
as the function name of every generated functions.  This
gives us 3 benefits:

1. We can avoid the ambiguous function name returned by
   LLVMLongName() in some special situation.

2. We don't need to have the art::Method object during
   the executable linking procedure.  Besides, this will
   make bootstrapping easier.

3. Reduce the size of the ELF executable, since we don't
   have to save a long function name, which usually contains
   more than 30 characters.

Change-Id: Ib698062b272458e847ad5545d7acf33a4dc9eb85
diff --git a/src/common_test.h b/src/common_test.h
index a323831..087168d 100644
--- a/src/common_test.h
+++ b/src/common_test.h
@@ -207,8 +207,10 @@
                                 reinterpret_cast<uint32_t>(invoke_stub)
 #if defined(ART_USE_LLVM_COMPILER)
                               , NULL,
-                                -1u,
-                                -1u
+                                static_cast<uint16_t>(-1u),
+                                static_cast<uint16_t>(-1u),
+                                static_cast<uint16_t>(-1u),
+                                static_cast<uint16_t>(-1u)
 #endif
                                 );
   }