Update RS driver to support extraction of global variable properties.

Bug: 20306487

This patch adds some new enums to classify properties (such as "static",
"constant", and "pointer") for global variables. The reference driver
is also extended to provide methods to examine these properties (when
the bitcode is compiled with bcc).

Change-Id: I331756f8a8990caf5ebdf85599060434a7cfdcb7
diff --git a/cpu_ref/rsd_cpu.h b/cpu_ref/rsd_cpu.h
index 6bfd913..0eed22c 100644
--- a/cpu_ref/rsd_cpu.h
+++ b/cpu_ref/rsd_cpu.h
@@ -97,6 +97,8 @@
         virtual const void * getGlobalAddress(int i) const = 0;
         // Returns the size (in bytes) of the global variable at index i.
         virtual size_t getGlobalSize(int i) const = 0;
+        // Returns the properties of the global variable at index i.
+        virtual uint32_t getGlobalProperties(int i) const = 0;
 
         virtual ~CpuScript() {}
     };