Remove PACKED attribute from QuickEntryPoints.

Setting the alignment to 4 can result in a misaligned data structure
on 64-bit platforms. So let's remove the PACKED attribute and allow
this data structure to take a natural alignment of the pointer width.

Change-Id: I0f70bd30abbe1c5db208368f68038f5689a24c9b
diff --git a/runtime/entrypoints/quick/quick_entrypoints.h b/runtime/entrypoints/quick/quick_entrypoints.h
index 2b9f2f3..26e5403 100644
--- a/runtime/entrypoints/quick/quick_entrypoints.h
+++ b/runtime/entrypoints/quick/quick_entrypoints.h
@@ -43,7 +43,7 @@
 class Thread;
 
 // Pointers to functions that are called by quick compiler generated code via thread-local storage.
-struct PACKED(4) QuickEntryPoints {
+struct QuickEntryPoints {
 #define ENTRYPOINT_ENUM(name, rettype, ...) rettype ( * p ## name )( __VA_ARGS__ );
 #include "quick_entrypoints_list.h"
   QUICK_ENTRYPOINT_LIST(ENTRYPOINT_ENUM)