Quick compiler: Method* as a reference

This is the first of two CLs intended to fix up and make consistent
the handling of references in the Quick backend.  A sibling
CL c/96237 updates the runtime to treat Method* as a compressed
reference when stored.  This CL makes a similar change for the
backend.

As far as the general handling of in-register references, though,
the current Quick backend is not consistent even for non-Method*
references.  Sometimes they are treated as references, but other
times are handled as if they were 32-bit ints.  A subsequent CL
will deal with that issue.

Change-Id: I5591c5eea6cca6ed22208ab806fd38b959c9d03d
diff --git a/compiler/dex/vreg_analysis.cc b/compiler/dex/vreg_analysis.cc
index 95b3d86..a4c62ad 100644
--- a/compiler/dex/vreg_analysis.cc
+++ b/compiler/dex/vreg_analysis.cc
@@ -425,6 +425,9 @@
     loc[ct->s_reg_low].defined = true;
   }
 
+  /* Treat Method* as a normal reference */
+  loc[GetMethodSReg()].ref = true;
+
   reg_location_ = loc;
 
   int num_regs = cu_->num_dalvik_registers;