Make ART compile with GCC -O0 again.

Tidy up InstructionSetFeatures so that it has a type hierarchy dependent on
architecture.
Add to instruction_set_test to warn when InstructionSetFeatures don't agree
with ones from system properties, AT_HWCAP and /proc/cpuinfo.
Clean-up class linker entry point logic to not return entry points but to
test whether the passed code is the particular entrypoint. This works around
image trampolines that replicate entrypoints.
Bug: 17993736

Change-Id: I5f4b49e88c3b02a79f9bee04f83395146ed7be23
diff --git a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
index 96903db..224756b 100644
--- a/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_trampoline_entrypoints.cc
@@ -19,6 +19,7 @@
 #include "dex_file-inl.h"
 #include "dex_instruction-inl.h"
 #include "entrypoints/entrypoint_utils-inl.h"
+#include "entrypoints/runtime_asm_entrypoints.h"
 #include "gc/accounting/card_table-inl.h"
 #include "instruction_set.h"
 #include "interpreter/interpreter.h"
@@ -504,7 +505,7 @@
         return 0;
       }
     }
-    JValue result = interpreter::EnterInterpreterFromStub(self, mh, code_item, *shadow_frame);
+    JValue result = interpreter::EnterInterpreterFromEntryPoint(self, &mh, code_item, shadow_frame);
     // Pop transition.
     self->PopManagedStackFragment(fragment);
     // No need to restore the args since the method has already been run by the interpreter.