[Compiler] Add object ref discovery

Previously, the compiler ran a type inference pass to identify floating
point uses for register allocation.  The grand plan involves moving
all type inference into the Art compiler driver (using the results from
verification).  As a short-term workaround, this CL adds object reference
discovery to the type inference pass.  This is needed for LLVM-IR generation.

Change-Id: I655806264181bfd26ab9340582a02c657cd3f678
diff --git a/src/compiler/codegen/x86/X86LIR.h b/src/compiler/codegen/x86/X86LIR.h
index 3646a1f..36e459c 100644
--- a/src/compiler/codegen/x86/X86LIR.h
+++ b/src/compiler/codegen/x86/X86LIR.h
@@ -137,11 +137,11 @@
 #define rNone   (-1)
 
 /* RegisterLocation templates return values (rAX, rAX/rDX or XMM0) */
-//                               location,     wide, defined, fp, core, highWord, home, lowReg, highReg,     sRegLow
-#define LOC_C_RETURN             {kLocPhysReg, 0,    0,       0,  0,    0,        1,    rAX,    INVALID_REG, INVALID_SREG}
-#define LOC_C_RETURN_WIDE        {kLocPhysReg, 1,    0,       0,  0,    0,        1,    rAX,    rDX,         INVALID_SREG}
-#define LOC_C_RETURN_FLOAT       {kLocPhysReg, 0,    0,       1,  0,    0,        1,    fr0,    INVALID_REG, INVALID_SREG}
-#define LOC_C_RETURN_WIDE_DOUBLE {kLocPhysReg, 1,    0,       1,  0,    0,        1,    fr0,    fr1,         INVALID_SREG}
+//                               location,     wide, defined, fp, core, ref, highWord, home, lowReg, highReg,     sRegLow
+#define LOC_C_RETURN             {kLocPhysReg, 0,    0,       0,  0,    0,   0,        1,    rAX,    INVALID_REG, INVALID_SREG}
+#define LOC_C_RETURN_WIDE        {kLocPhysReg, 1,    0,       0,  0,    0,   0,        1,    rAX,    rDX,         INVALID_SREG}
+#define LOC_C_RETURN_FLOAT       {kLocPhysReg, 0,    0,       1,  0,    0,   0,        1,    fr0,    INVALID_REG, INVALID_SREG}
+#define LOC_C_RETURN_WIDE_DOUBLE {kLocPhysReg, 1,    0,       1,  0,    0,   0,        1,    fr0,    fr1,         INVALID_SREG}
 
 enum ResourceEncodingPos {
   kGPReg0   = 0,