More MIPS fixes. Many run-test tests pass.

Run-test tests 001-043 work, including 003-omnibus-opcodes. 044 is
proxy, which is still broken.

Changes made:
- Fixed argument marshalling of FP values for calls to helper functions
  in the compiler.
- Fixed CheckCast compilation's mistaken use of rARG0 instead of rRET0.
- Fixed conversion calls to marshall FP arguments properly.
- Created named values for FP args, though they differ in MIPS only.
- Fixed assembly to always use T9 to hold code pointer to jump to.
- Fixed proxy offset values.

Change-Id: If121db322683a307e5a1016210f4f73283aa817c
diff --git a/src/compiler/codegen/mips/FP/MipsFP.cc b/src/compiler/codegen/mips/FP/MipsFP.cc
index 437f1ed..990c71f 100644
--- a/src/compiler/codegen/mips/FP/MipsFP.cc
+++ b/src/compiler/codegen/mips/FP/MipsFP.cc
@@ -197,11 +197,11 @@
   oatFlushAllRegs(cUnit);
   oatLockCallTemps(cUnit);
   if (wide) {
-    loadValueDirectWideFixed(cUnit, rlSrc1, r_FARG0, r_FARG1);
-    loadValueDirectWideFixed(cUnit, rlSrc2, r_FARG2, r_FARG3);
+    loadValueDirectWideFixed(cUnit, rlSrc1, rFARG0, rFARG1);
+    loadValueDirectWideFixed(cUnit, rlSrc2, rFARG2, rFARG3);
   } else {
-    loadValueDirectFixed(cUnit, rlSrc1, r_FARG0);
-    loadValueDirectFixed(cUnit, rlSrc2, r_FARG2);
+    loadValueDirectFixed(cUnit, rlSrc1, rFARG0);
+    loadValueDirectFixed(cUnit, rlSrc2, rFARG2);
   }
   int rTgt = loadHelper(cUnit, offset);
   // NOTE: not a safepoint
diff --git a/src/compiler/codegen/mips/MipsLIR.h b/src/compiler/codegen/mips/MipsLIR.h
index 5077c9f..4b7da55 100644
--- a/src/compiler/codegen/mips/MipsLIR.h
+++ b/src/compiler/codegen/mips/MipsLIR.h
@@ -301,6 +301,10 @@
 #define rARG1 r_ARG1
 #define rARG2 r_ARG2
 #define rARG3 r_ARG3
+#define rFARG0 r_FARG0
+#define rFARG1 r_FARG1
+#define rFARG2 r_FARG2
+#define rFARG3 r_FARG3
 #define rRET0 r_RESULT0
 #define rRET1 r_RESULT1
 #define rINVOKE_TGT r_T9