Quick backend: rename target-specific #defines

Another step towards a single compiler.  The #include build mechanism
relies on macros with the same name to take on different values for
our various targets.  This CL prepends a target-specific string
(and exposes some needed by common code as functions rather than #defines).

Macros and #defines still available for use from target-dependent code,
but functions added for target independent use.  For example,
rRET0 for Arm becomes rARM_RET0 in target-dependent code, and
targetRegister(kRet0) in target-independent code.

No logic changes, other than adding functions to return previously #defined
values.  As of this CL, the primary target includes, xxxLIR.h, have no
macro collisions.

Change-Id: I5e11df844815b7d129b525a209dd7c46bd9a4a09
diff --git a/src/compiler/codegen/CodegenUtil.cc b/src/compiler/codegen/CodegenUtil.cc
index 2450058..b0a1e44 100644
--- a/src/compiler/codegen/CodegenUtil.cc
+++ b/src/compiler/codegen/CodegenUtil.cc
@@ -258,7 +258,7 @@
     PromotionMap vRegMap = cUnit->promotionMap[i];
     std::string buf;
     if (vRegMap.fpLocation == kLocPhysReg) {
-      StringAppendF(&buf, " : s%d", vRegMap.fpReg & FP_REG_MASK);
+      StringAppendF(&buf, " : s%d", vRegMap.fpReg & fpRegMask());
     }
 
     std::string buf3;